How do I do a clean uninstall?

Dec 15, 2014 at 6:41 PM
After I retract the deployment of the solutions in the SP2010 Central admin, I get some innocuous but annoying 'Missing server side dependencies" errors, which in turn give me errors when I do a database upgrade:

[MissingWebPart] WebPart class [5607d114-2868-07bc-a0e0-2eb839baa603] (class [KWSResourceBooking.KWSResourceCalendar.KWSResourceCalendar] from assembly [KWSResourceBooking, Version=1.1.4772.37196, Culture=neutral, PublicKeyToken=7613c4c8d1d024e4]) is referenced [1] times in the database [Sharepoint_MGIT_Teamsite], but is not installed on the current farm. Please install any feature/solution which contains this web part. One or more web parts are referenced in the database [Sharepoint_MGIT_Teamsite], but are not installed on the current farm. Please install any feature or solution which contains these web parts.

How can I do a clean uninstall?