SharePoint Online: Remove User or Group from List Permissions using PowerShell

Requirement: Remove user or group from list permissions in SharePoint Online using PowerShell

How to Remove User Permissions from a List in SharePoint Online? 
To remove a user or group from SharePoint Online list permissions, follow these steps:

• Navigate to your SharePoint Online list or library. 
• Click on Settings gear >> Select "List Settings" 
• In the list settings page, Click on "Permissions for this List" under "Permissions and Management" group
• If the List is not using unique permissions, Click on "Stop Inhering Permissions" button and confirm the prompt.
• Now you can remove the user or group from the list permissions by selecting the user and clicking on "Remove User Permissions" button from the ribbon.

PowerShell to Remove User from List Permissions in SharePoint Online
Here is the SharePoint Online PowerShell to remove permissions

#Load SharePoint Online Assemblies
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.dll"
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.Runtime.dll"

#Remove User from List Permissions
Function Remove-SPOUserFromListPermission($SiteURL,$ListName,$UserAccount)
{
    #Setup Credentials to connect
    $Cred = Get-Credential
    $Cred = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($Cred.UserName,$Cred.Password)
 
    Try {
        #Setup the context
        $Ctx = New-Object Microsoft.SharePoint.Client.ClientContext($SiteURL)
        $Ctx.Credentials = $Cred
     
        #Get the List
        $List=$Ctx.Web.Lists.GetByTitle($ListName)
        $Ctx.Load($List)
        $Ctx.ExecuteQuery()
        
        #Get the User
        $User = $ctx.Web.EnsureUser($UserAccount) 
        $Ctx.Load($User)
        $Ctx.ExecuteQuery()
 
        #Break Permission Inheritance
        $List.BreakRoleInheritance($true, $false)
        $Ctx.ExecuteQuery()

        #Get List Permissions
        $Ctx.Load($List.RoleAssignments)
        $ctx.ExecuteQuery()
        
        #Remove Group from List Permissions
        $List.RoleAssignments.GetByPrincipal($User).DeleteObject()
        $Ctx.ExecuteQuery()
 
        write-host  -f Green "User '$UserAccount' has been Removed from List '$ListName'"
    }
    Catch {
        write-host -f Red "Error:" $_.Exception.Message
    }
}

#Variables for Processing
$SiteURL = "https://crescenttech.sharepoint.com/Sales"
$ListName = "Documents"
$UserAccount = "Salaudeen@TheCrescent.com"
 
#Call the function to Remove user from List Permissions
Remove-SPOUserFromListPermission -SiteURL $SiteURL -ListName $ListName -UserAccount $UserAccount

PnP PowerShell to Remove User from List Permissions:

#Config Variables
$SiteURL = "https://crescenttech.sharepoint.com/Sales"
$ListName ="Documents"
$UserID= "i:0#.f|membership|Salaudeen@TheCrescentTech.com"

#Connect PNP Online
Connect-PnPOnline -Url $SiteURL -Credentials (Get-Credential)

#Get the Context
$Context = Get-PnPContext
 
#Get the list & User objects
$List = Get-PnPList -Identity $ListName
$User = Get-PnPUser -Identity $UserID

#Break Permission Inheritance
Set-PnPList -Identity $ListName -BreakRoleInheritance -CopyRoleAssignments

#Remove User from List Permissions
$List.RoleAssignments.GetByPrincipal($User).DeleteObject()
$Context.ExecuteQuery()

SharePoint Online: Remove Group from List Permissions using PowerShell CSOM

#Load SharePoint Online Assemblies
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.dll"
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.Runtime.dll"

#Remove Group from List Permissions
Function Remove-SPOGroupFromListPermission($SiteURL,$ListName,$GroupName)
{
    #Setup Credentials to connect
    $Cred = Get-Credential
    $Cred = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($Cred.UserName,$Cred.Password)
 
    Try {
        #Setup the context
        $Ctx = New-Object Microsoft.SharePoint.Client.ClientContext($SiteURL)
        $Ctx.Credentials = $Cred
     
        #Get the List
        $List=$Ctx.Web.Lists.GetByTitle($ListName)
        $Ctx.Load($List)
        $Ctx.ExecuteQuery()
        
        #Get the Group
        $Group = $Ctx.Web.SiteGroups.GetByName($GroupName) 
        $Ctx.Load($Group)
        $Ctx.ExecuteQuery()
 
        #Break Permission Inheritance
        $List.BreakRoleInheritance($true, $false)
        $Ctx.ExecuteQuery()

        #Get List Permissions
        $Ctx.Load($List.RoleAssignments)
        $ctx.ExecuteQuery()
        
        #Remove Group from List Permissions
        $List.RoleAssignments.GetByPrincipal($Group).DeleteObject()
        $Ctx.ExecuteQuery()
 
        write-host  -f Green "Group '$GroupName' has been Removed from List '$ListName'"
    }
    Catch {
        write-host -f Red "Error:" $_.Exception.Message
    }
}

#Variables for Processing
$SiteURL = "https://crescenttech.sharepoint.com/Sales"
$ListName = "Documents"
$GroupName = "Sales Portal Members"
 
#Call the function to Remove group from SharePoint List permissions
Remove-SPOGroupFromListPermission -SiteURL $SiteURL -ListName $ListName -GroupName $GroupName

PnP PowerShell to Remove Group from List Permissions

#Config Variables
$SiteURL = "https://crescenttech.sharepoint.com/Sales"
$ListName ="Documents"
$GroupName= "Sales Portal Members"

#Connect PNP Online
Connect-PnPOnline -Url $SiteURL -Credentials (Get-Credential)

#Get the Context
$Context = Get-PnPContext
 
#Get the list
$List = Get-PnPList -Identity $ListName
$Group = Get-PnPGroup -Identity $GroupName

#Break Permission Inheritance
Set-PnPList -Identity $ListName -BreakRoleInheritance -CopyRoleAssignments

#sharepoint online powershell remove group permissions
$List.RoleAssignments.GetByPrincipal($Group).DeleteObject()
$Context.ExecuteQuery()

To Add user or group to SharePoint Online list or library permissions: SharePoint Online: Grant Permission to List or Library using PowerShell