LMIV - 1987 - fork seals and repair

[bentombed]

Hello,

I need to replace the forkseals on my 87 lemans, the bike has the adjustable forks and stock big wheel. As far as i can tell, i should be able to remove the lower fork legs with the screw at the base, and refil the fork oil by removing the big nut on the top.  is that it? i cannot find a guide for this job anywhere. 
also how much fork oil and what weight will i need?   I have done this job a bunch of times on old BMWs but not with a guzzi cartridge forks.

thanks in advance

[Cdn850T5NT]

I have (from many years past... though not yet installed :( ) a set of Shraeder valves for the fork drains for my T5.  This allows me to use a syringe to fill the fork tubes with ATF (Dexron...) for my bike, through the fork drains.  I prefer this as loosening the nut up top requires slackening the upper triple clamp clamp-nut, and I don't want to do that.