I had done transmission fluid and filter 3 weeks ago for my 3.0. It's not difficult to change transmission fluid. When you replace filter, there are 2 seals/O-rings for filter and when you're pulling down the old filter, making sure the filter rubber O-ring is not stuck in transmission.
Recommend use Dexron - VI transmission fluid for only GM transmission (i guess your X transmission is GM)
I can't imagine how dirty my X transmission fluid when i changed it at 90K miles. Fluid was dark and dirty with a lot of small metal dirts.
Here is OEM transmission fluid for GM transmission with part number.
