It might be worth trying a tip I saw on another forum for getting rid of small amounts of sag. Turn bike upside down, lower reverb whilst upside down being careful not to allow it to extend, put bike right way up and extend reverb again. No idea why it works, but it did on my older model Reverb (A2, I think) and for quite a few others it seems.
Otherwise, as has been said, the service is quite long but fairly straight forward. In my case, the final bleed of the spring turned into a pita when the bleed tool decided it had had enough and puked out everything, meaning I had to start over again. Done it a couple of times now, though, and it’s fine now.