First thing you need to do, is turn off your printer, and remove the maintenance panel on the left side. Put a BUNCH of paper towels in there on the bottom. Slide the head over there like you are cleaning it.
To remove the head cover if you havent done it before, there are two small phillips screws on the head cover. Not the big flathead plastic screws for raising or lowering your print head... when you take that off, you will see 8 white plastic ipod looking things held in place with two metal clamps (those are your dampers). The metal clamps pull straight up off the top of the damper. Pay attention to how those sit on there, it will be important to remember later. (take a picture if you have to.)
The dampers pull straight up out of the head assembly, and it's straight forward from there. Once you get the new dampers on there (or just the one depending if you want to buy one now, and replace the rest as they go bad sporadically from now on), you can either push and tape the valves open behind the ink cartridges on the back of the machine, or do an ink fill from your maintenance menu. If you do an ink fill, lower your head all the way so you are sure to get a good seal with the capping station.. the pump will pull the ink and fill your dampers for you. You will waste more ink this way than gravity feeding your dampers by opening the damper and the valve up top... but its quicker.
I just went through something kind of similar, so send me a pm if you have any questions. Good luck!
