Air Dryer issue

[SFMEACH]

I had my BB in for a service check and the mechanic said that the air
dryer was not working properly and that it would be cheaper and easier
just to replace the old air dryer with a newer version. I guess it is
supposed to purge each time it comes up to pressure and mine did not do
it. What is the process to replace the parts of the original air dryer
(84 FC35)? Is this within the capabilities of a fairly handy but BB
novice owner? I am assuming that the parts would be cheaper if I do it
myself vs replacement. The replacement part was an AD-9 (I think that
is what the parts dept said) for $317 plus labor of about $150. I
might be able to get a discount on the air dryer to about $200-250.

Steve Meach
84 FC35