take it off the gun,
then remove the elbow fitting, carful it is loctited in place, you may need to heat it to get it out
one you have the elbow out simply unscrew the 2 halves
with the top half you will need to remove the brass pistons and 16 washers which sit on it. also there is a no. 015 oring on the top where it screws into the gun.
with the bottom half, put it upside down on a table and push the swivel collar down and remove that, then use a 1/8" allen key to take the adjuster screw out...it comes out of the top, NOT down thru the bottom.
once the adjuster is out there are 3 orings on the bottom half to remove, 2x no. 016 which were under the swivel and one no. 010 which sits inside the hole where the adjust came out.
job done.
when reassembling, id use new orings all round and take note of the following....
when replacing the collar, put a generous amount of vaseline on both the no.016 orings and inside the collar and be careful not to pinch the orings as you push it back on (usually the top one gets caught)
push the adjuster down with an allen key till it clicks into place then start turning it from the underside.