A pump-up is not necessary...just precautionary. Just be careful not to spill ink inside the head carriage when you are moving/removing dampers.
I suggest stuffing paper towels in there while you re working to catch stray drop/drips. Also have a paper coffee cut handy to help manage the dampers and open ink lines.
Specifically, the dampers may leak a bit when you loosen and remove the ink line fittings. Be sure to catch it before it becomes an issue. (The ink will move back toward the cartridges when you loosen the ink line fitting to the damper).You'll also have to draw the ink through the head (or at least to fill the damper) manually.
Just be careful. You'll be fine.