Depends on how involved you want to get.
To do it right, you should remove the forks from the tripletrees, that isn't too hard, but does take some time.
Or you can skimp out and just remove the cap, take the springs out, suck all the oil out, place alittle new oil in it, pump the fork a few times, suck it out again, and put the new springs and oil in it, and put the cap back on.
The forks in these are simple, not like sport bikes or mx bikes with all the dampener and valving stuff, but it is nice to remove and imspect that. You would have to remove the forks to change the seals.
But make sure you hold the cap on when you unscrew it, it's alum, and strips easily, and it is under pressure. You just have to hold it down good when removing, I found it harder to put it on, attempting to find the starting point while attempting to position and hold it down.