Think overdrive not transmission. Two different items. The OD is a lot simple to R&R than the tranny. Much of that is due to the 30 lbs of OD vs the 100+ of the tranny.

If your failure to engage or consistently engage is the actuating piston seals, most shops will not just do those seals, they will attempt to sell you a whole unit. Wait till you hear the price. The difference between what you would pay for a few tools and a Saturday afternoon might cure your fear of working on this unit. You could do it for about $40 in parts from me, plus the cost of any tools you would not have.

Have you looked at the 700-900 FAQ under Overdrive Rebuild: M46 OD on what is entailed??

Duane