ET is correct you would need to edit the table.
In the "Database Manger" on the primary SolarWinds box this is what your table should look like.
Make the change to the other Web server you wish to be primary.
and that's it. The only problem is that if you run the "Configuration Wizard"it will change this back, so you will have to rinse and repeat every-time you run it to switch it back.
Thank you,
-Terrance