Engine/Transmission (1998.5 - 2002) transmission Pm ?

[Fsbigcountry]

Well 120,000 miles now. Don't know about the first 100,000 but since I've had it several oil chgns, air filter & fuel filter and now fp gauge & new fact. lift pump. Am going on long trip towing tt in june. Thinking about changing fluid and filter in transmission. also read bands are supposed to be ajusted. Is this ness? Is it very technical? Seems like every time I changed transmission filter in one of my old cars, the transmission went out shortly thereafter. This ever happen to anyone else? I sure don't want to mess up my transmission. Will be lookig at the brakes also, hopefully I wont run into problems there. Any info would be appreciated. Thanks