This is for when the clean up wizard is borking out and repeatedly running it doesn’t feel like its making any progress (not that it tells you anyway).
The server/instance name to connect to with SSMS is:
\\.\pipe\MSSQL$MICROSOFT##SSEE\sql\query
If the above doesn’t work then just uninstall WSUS and start again… its not that painful apart from the amount of crap you have to download.