Summary

This is kind of similar requirement from my previous blog article.

How to remove users from multiple Azure AD Groups?

But in this article I will provide only the code for removing the Site collection Admins from SharePoint Site. The steps for running this code is same as the above article.

$Users2Remove = (
    "BobK.GOV963094.onmicrosoft.com",
    "DebraB.GOV963094.onmicrosoft.com"
)

$ClientId = "7c244c08-9875-4ffe-b39d-34f9b6853f6b"
$Tenant = "gov963094.onmicrosoft.com" # replace your tenant name

Import-Csv C:\Contoso\teamSites.CSV | 
    ForEach-Object {
        try
        {
            $newSiteUrl = $_.SiteURL
            $newSiteConn = Connect-PnPOnline -ClientId $ClientId -Url $newSiteUrl -Tenant $tenant -CertificatePath 'MyPnPApplication.pfx' -ReturnConnection

            # Get the site collection administrators  
            $scaColl = Get-PnPSiteCollectionAdmin -Connection $newSiteConn
            foreach($sca in $scaColl)  
            {          
                Write-Host $sca.LoginName
                $modifiedLoginName = $sca.LoginName
                $modifiedLoginName = $modifiedLoginName -replace "i:0#.f\|membership\|", ""
        
                if ( ( $Users2Remove -contains  $modifiedLoginName ) -eq $true )
                {
                    Write-Host $("Remove {0}" -f $sca.LoginName)
                    Remove-PnPSiteCollectionAdmin -Owners $sca.LoginName
                    Write-Host $("Removed..")
                }
            }         
        }
        catch
        {
            $ErrorMessage = $_.Exception |  Out-String
            Write-Host $("Exception {0}" -f $ErrorMessage);
        }
        finally
        {
            Write-Host $("Disconnecting to {0}" -f $newSiteUrl);
            Disconnect-PnPOnline -Connection $newSiteConn
            Write-Host $("Disconnected to {0}" -f $newSiteUrl);
        }
    }