buy the proper filter and fluid. The dealer told me there was a part number split between years in 07 and their filter was 40.00; however, I bought a 14.99 filter from autozone and compared the two and they were the exact same. The fluid was special stuff and I could only locate it at the dealer for 8.99 a qt.
on the passenger side of the trans locate a gold in color bolt, if i remember correctly it was 19mm. it side this lug bolt thing is the fill level dip stick (separate, not the same part) and I read some where that even just doing the drain then fill it was about 8qts. T bought 9 but still can't confirm this as I haven't gotten around to do it.
so locate the thing above, then drain the fluid, then remove the pan, then remove the filter, clean the magnets on the pan. then replace everything. Now for filling it up you can either run a tube down to the fill hole from above (funnel, tube, trans (make since?) and slowly fill it up, or you can use something like a motive transfer pump... once it reads "full" replace the bolt. I was told by the dealer to then start the truck and slowly shift through all gears.. like R.........N...........D..........1 and so on.. Like a 1 to 5 count all the way through and back to Park. Then climb back under the truck and check the trans level. fill as needed to top off.
also a rule of thumb would be to try and make sure the truck says as level as can be so you don't get any false fulls..