Restore botched changed to original

[Brian Keener <bkeener at thesoftwaresource dot com>]

I have been working on a change for the Cygwin Setup program and now have 
managed to botch up my version of choose.cc completely.  I made a copy of 
my version and did a cvs diff - so I know what is different and I wanted 
to put my copy back to the master cvs version.

I know I can retype my changes but is there another way to revert back 
(say for example) by doing a 

cvs checkout cinstall/choose.c

or something of that nature.

I did look at the man pages but really couldn't find this.