how to you need to have them both out of the bike thats the best part
then they are pretty self explained after that. start with the end cap and then remove the spring etc but in saying that i havent had the joy of doing a set of upside down ones yet the trick is undoing the piston bolt as piston spins as its loosend but can usualy get away with small broom stick down the centre of the fork. check and recheck seal surface for marks etc and clean all the oil out start a fresh as a small amount of extra oil can change everything in your handling measure oil accureatly when refilling and remember just take your time no rush rushing costs you money i would be surprised if there is to much difference with the upside down forks
To get upside down fork seals out you'll want a spring compressor.
Once you've compressed the spring, got the cap of it and released the spring and removed it, you pry the dust seal down, then remove the circlip, having someone hold the outer, keep slamming the inner like a slide hammer and it will hammer the seal out.
Gently remove the bushes and the fork seal plus the dust seal can be slid off.
use some cling warp or saren wrap or whatever it's called on the end of the tubes when you slide the new seals on so the tube end can't damage them.
I made my own tools for compressing the spring, pumping the damper rod and adjusting the level.
Fork spring compressor:
Compressed, now the cap can come off.
Damper rod holder
I apply a vacuum to the tube to suck out excess fluid to set the level