Here's how I modified my Quickcam for astronomy

Total cost of everything but the Quickcam was about $4.00. Total construction time was about 90 minutes; about 40 minutes of that was trying to get the circle cutter to make exactly the right sized hole to hold the fitting for drilling.

Here are some photos! Click the images for larger versions.
All parts
All the parts used in the assembly

View of CCD inside
A view of the CCD chip

Complete assembly
The complete assembly, including part of an Arby's kid's meal toy, which was JUST the right size to cap the fitting!