You do not have to drop the trans out of the car to get to the solenoids. But if you want to pull the trans out to do this job, the bolt you are talking about is the one between the back of the engine and the tube of the trans correct? Look on the end of the trans at the front of the engine, there is a plate there that connects the end of the trans to the engine. Remove this plate and with a long 1/2 in. extinsion and a breaker bar you should be able to go down the side of the engine to get to the bolt you have to remove.
I can get at it without taking the tranny out? I need to take the side cover off the tranny, right?