I have done this 3 times in 107,000 miles. I make a mess every time so I use the cardboard. I like Rfishin's idea of installing a drain plug. I changed fluid every 30,000 miles and never noticed debris in the filter as others have said, but noticed a lot of stuff on the magnet on the bottom of the pan. After draining the pan and replacing the filter and cleaning the magnet. I reinstall the pan bolts and disconnect the trans line going to the cooler and keep adding fluid until the fluid comes out clean, then reconnect and top off fluid. If I was going to do this again I would add another magnet to the bottom of the pan because I think it collects more stuff than the filter. Also I would stay with the original OEM gasket, the rubber gasket I used from the filter kit leaked and after re torqueing several times I had to go back to the OEM gasket to stop the leak.
