HELP..transmission flush

Ok guys this is my 2nd attempt at this. i dont have time today to run thru old posts. I have 05 tacoma with the "sealed" 5spd auto trans. mated to the 4.0 v6. The truck has exactly 100,680 miles on it. Im not sure of the trans. service that has been done in the past since im the 2nd owner. The dealer says FLUSH it at 100k...I've heard flushes CAN be bad, so CAN just a drain and refill....which should i do??? I dont want to loosen up crap inside with a flush..but a drain and refill seems like a half-ass job...which should i do??????????????

 

Here ya go...

http://www.tacomaworld.com/forum/2nd-gen-tacomas/68462-diy-full-flush-automatic-transmission.html