With the rear off the ground as HeyYou stated. Tighten the adjusters pretty tight(a couple extra turns), after you can't rotate the wheel(this will center the shoes) Then back the adjuster off until the wheel rotates with a little resistance, as HeyYou also stated.

 

Use two screwdrivers to back the adjuster off... use one to push the self-adjuster out of the way, so you CAN turn the adjuster back a bit.

I usually just adjust 'em up, step on the pedal a couple times, then recheck adjustment.

 

And if the access hole is not opened?

 

And if the access hole is not opened?

 

My 98 had no hole either. I used a 1/4" angle die grinder and made 2 slots.