Just in case anyone is in the same boat I am, I tried following these instructions to the letter for a long time (several days for about 5 minutes each :-P ) and kept getting the following error:
But a quick look at sourceforge's checkout howto page directed me to change the url to:
[nitrogen:zEvolution]$ svn co http://zimbraevo.svn.sourceforge.net/viewvc/zimbraevo/trunk/ .
svn: PROPFIND request failed on '/viewvc/zimbraevo/trunk'
svn: PROPFIND of '/viewvc/zimbraevo/trunk': 301 Moved (http://zimbraevo.svn.sourceforge.net)
Revision 2: /trunk