Remove lost/broken Webparts

Previously, I retracted a solution from my web application. The consequence of this action was that I was not able to load the pages anymore. I recieved:

Error

An error occurred during the processing of . Could not load file or assembly 'Solution.WebParts, Version=1.0.0.0, Culture=neutral, PublicKeyToken=a7985c93d0151889' or one of its dependencies. The system cannot find the file specified.

In this case, the only thing you have to do is to remove the webpart. Removing the webpart in the webpart gallery doesn't solve this.

Solution:
Append ?Contents=1 to the webpart page's URL to display the Webpart Maintenance Page. On that page you can delete the malefactor.

Example: http://moss/default.aspx?contents=1