The service is stopped via the IIS Manager, as it runs as a web site.
The Web Statistics button in Plesk points to the non-SSL stats.
Currently, there is no separate button for viewing SSL-traffic statistics.
You can use a tool like CCleaner to remove temporary files and old server system updates to give yourself some breathing space.
Under "Options" in the WSUS admin tool, you can find the cleanup wizard.
As a security measure, your web statistics report is password protected.
The login information was initialized to be the same as your FTP login when the Windows hosting plan was first created.
The database in WSUS is an embedded SQL Server database (SQL Server Express).
It can be managed via SQL Server Management Studio. Note: There are many versions of Management Studio.
This does not necessarily remove disk files you would expect and can need some encouragement by manually "unapproving" updates under "All Updates".
Follow the steps here to deselect updates you don't ever want and remove all updates from disk.
By removing all updates from disk and running a reset, it will start downloading those updates again; this delete is nothing to worry about.