How to Deploy and Activate Sandboxed Solutions in SharePoint?
Sandboxed solutions bring the benefit of deploying solutions to the SharePoint Server without affecting any other process outside the sandbox. SharePoint 2010 Sandboxed solution can be deployed by Site collection administrators. Here is the guide on How to Deploy and activate sandboxed solution in SharePoint 2010.
Go to Site Actions >> Site Settings >> Solutions under the Galleries
In Solutions tab, click Upload Solution button
 Browse and select the WSP File from your sandboxed solution, click on “OK” to complete.The solution package is now in the site collection’s solution gallery, but it is not yet deployed. In the Activate Solution dialog box, click Activate to activate the solution
You will see the solution’s activation status in the solution Gallery page.
Depending on the solution, will see the sandboxed solution in action.
From the solution gallery page, we can deactivate, delete the solution further.
Using PowerShell to Deploy and Activate Sandboxed Solutions:
To upload a sandboxed solution to a site collection’s Solution Gallery with PowerShell,
Add-SPUserSolution -LiteralPath d:\PrintListPackage.wsp -Site https://sharepoint.crescent.com/sites/dev
To activate the Sandboxed solution use: Install-SPUserSolution cmdlet
Install-SPUserSolution -Identity PrintListPackage.wsp -Site https://sharepoint.crescent.com/sites/dev
To Uninstall the Sandboxed solution:
Uninstall-SPUserSolution -Identity PrintListPackage.wsp -Site https://sharepoint.crescent.com/sites/dev
To Remove the Sandboxed solution:
Remove-SPUserSolution -Identity PrintListPackage.wsp -Site https://sharepoint.crescent.com/sites/dev