Changing the filters has been beat to death over the years.
It is pretty simple. the secondary filter, (Large one) just remove the large bolt in the center of it. think it is 22mm. hold the filter in one hand, and loosen the bolt. either hold the filter and turn the bolt, or hold the bolt and turn the filter.
place some rags under it, it will be brim full of fuel.
I have a one gallon oil bottle with the side cut out, I use to put the filter in as soon as itd rops off the bolt.
Your 85 will have 2 rubber "O" rings on the bolt. if they are sort of flattened, replace them. Fill the filter with ATF, or Diesel purge, this way you won`t have dirt or contaminates that could be in a fuel can.
wipe the filter base with a clean cloth, make sure the gasket is lubed with fuel, which it probably will be anyway. screw the filter down on the bolt. hold the filter, and tighten the bolt.
I give the primer a few pumps, but if the filter if filled to the top, the engine should kick right over. hold the peddle down to a fast idle in case it hick-up a little.
The inline clear filter is just 2 hose clamps, pull it off, and stick on the new one. fuel might come out of the supply line if the tank is full. its just gravity feed.
There will always be a small bubble in the filter, this is normal.
Here is an old filter thread. Whunter has a link, second post, but more info on down below.
http://www.peachparts.com/shopforum/showthread.php?t=112664
The small return lines just pull off. just be careful not to damage the nipples on the injectors, some times when the hoses are old, the rubber tears at the nipple, leaving a short piece on. just don` knick the barbs.
the last injector at the rear on the engine, has a plug in it. just remove it, and stick it in a short piece of new hose.
Charlie