It really is that simple mate, just loosen the back cap and pull the whole bolt kit out to the rear, then remove the o-ring on the tip of the bolt, unscrew the beer can from the manifold and remove the bolt- job done. Lube it all and put it back together, making sure when you re-insert it that the one grub screw sticking out goes into the groove inside the bottom of the body. Dead easy and there are plenty of other online guides and pics out there.
If you plan on using a PMR you will need to learn to do it; the way to run into problems with those guns is not to maintain them regularly, as when the lube wears off they start shredding o-rings etc. If you have any problems the guys at DYE are very helpful but you should be fine
