Fixing a CMSSW release on red is quite simple.  Use xcmsi to release the software (see other docs).  Once the CMSSW is released and scramv1 acknowledges the release (scramv1 lists CMSSW) then modify two files in the release area.
In the directory $CMS_ROOT/cms/Releases/CMSSW/CMSSW_x_y_z/config/
change the Buildfile and Buildfile.tmpl to the build file listed in Aaron's post about fixing CMSSW buildfiles to compile on 64-bit machines.  Done.