Guide to Upgrading from free Domain Mapping to WPMU's version

I am already running a WPMS and find the free domain mapping plugin clunky to use especially not having cross site cookies. I want to switch but don't want to mess up my current setup. Do you guys have a guide on how to do this for a site that's in production?

I found the answer at here.
As I suspected, it's a simple ftp file replace. I kept a back up of my old sunrise.php as sunrise-old.php and left the old plugin there just network disabled. Because it's good to have a quick fallback.