When you get to Payless' office (out the airport north exit and left at first light) you are already on your way to Disney.
From their lot go right instead of their suggest left (Frontage Rd.). Less than a mile is next light (Conway), take two lefts to get onto 528 (Beach Line) west. Down what looks like an exit ramp to pay the toll in cash, then back onto 528 all the way to end (I-4); go west (bear left) for Disney.
Used Payless at MCO many times without problems. Once they let me pick up my car early, once they would not unless I upgraded at extra cost.
Returning via I-4 East to 528 east, go down what looks like an exit ramp to pay the toll. Get off 528 at its exit 9 (Tradeport). Left and cross under. Get into middle lane, required right onto McCoy (becomes Frontage). Payless is on the left near the toll booth which you are not going through. (Keep going would be to the airport; right less than a mile (436; Semoran) to go in the north entrance.)