This webcam has a design flaw, that often leads to a broken hinge on the base.
That is also why you will find it quite cheap on ebay.

Here a two adapters for it:

#1
You need to remove the broken base (I just cutted it of) and afterwards the adapter just clicks on the ball.

#2
Just twist/cut off the old mount completely and glue the adapter to the backside of the webcam