Sharepoint - How to change the user profile property value for all users via PowerShell?
You can iterate through all user profiles and update them. The PowerShell script can look like this:
[void][reflection.assembly]::Loadwithpartialname("Microsoft.Office.Server");
Add-PSSnapin Microsoft.SharePoint.PowerShell
$site=Get-SPSite "https://yourSitecCollection"
$serviceContext = Get-SPServiceContext $site;
$upm = new-object Microsoft.Office.Server.UserProfiles.UserProfileManager($serviceContext);
$userProfile = $upm.GetUserProfile("[email protected]");
foreach($userProfile in $upm)
{
$userProfile["PropertyName"].Value = "Test Value";
$userProfile.Commit()
}