Procedure for making changes to CVS

[Casey Muratori]

A friend and I would like to take a week off from our jobs and spend the
time fixing some problems we've had with CVS.  I read the cvshome.org
page, and it was very clear about the procedure for downloading the source
code.  However, it was not clear about how to submit changes back to the
source tree.  Could someone please point me to the web page where this
process (or the process of signing on as a CVS developer) is explained?

Thanks,
- Casey