Installing cvsup can be done simply by using the port with the following commands
# cd /sr/ports/net/cvsup-without-gui/
# make install
# cvsup -L2 -g -h cvsup.freebsd.org /usr/share/examples/cvsup/ports-supfile
The -g flag tells cvsup to run without a gui, the -h refers to the host of cvs server. The host can be set within ports-supfile