Removing owner from all OneDrives....

Kotus-Tech 

Prerequisites:

• SharePoint Online PowerShell module
• This script users ‘Set-SPOUser’ cmdlet. You must have the SharePoint Online global administrator permission to run the cmdlet.

Add Secondary Site Collection Admin for all OD4B Users:

Using the below Powershell script you can add the secondary site collection admin for all OD$B users.

In the script, replace the AdminURL and SecondaryAdmin with correct values.

Function Add-OnedriveSecondaryAdmin($AdminURL,$SecondaryAdmin)
{
    #connect Spo service.
    Connect-SPOService -Url $AdminURL
    #Get all Onedrive URL's.
    $OneDriveURLs = Get-SPOSite -IncludePersonalSite $true -Limit All -Filter "Url -like '-my.sharepoint.com/personal/'"
    foreach($OneDriveURL in $OneDriveURLs)
    {
        #Add Secondary administrator to Onedrive Site.
        Set-SPOUser -Site $OneDriveURL.URL -LoginName $SecondaryAdmin -IsSiteCollectionAdmin $True -ErrorAction SilentlyContinue
        Write-Host "Added secondary admin to the site $($OneDriveURL.URL)" 
    }
}
Add-OnedriveSecondaryAdmin -SecondaryAdmin "email address removed for privacy reasons" -AdminURL "https://Tenantname-admin.sharepoint.com"
                    

Remove Secondary Site Collection Admin for all OD4B Users:

To remove the secondary site collection admin, in the above script, just change the Set-SPOUser cmdlet’s parameter “IsSiteCollectionAdmin” value to $false.