what tools do i need to do a transmission flush on my 2007 pontiac g6 4 cylinder

Basic set of 1/4 drive metric sockets. The pan bolts will be either a 8mm, 10mm, 11mm, or 13mm. And you will need a 4" extension. Loosen each bolt 3/4 of a turn then pick a corner and loosen that bolt 1 turn, then the two on either side of it loosen 1 turn and work your way on a v. When you get half way to the next two corners loosen the rest of the bolts to that corner 1/2 turn. The corner you chose will start to come down keeping the rest of the pan gasket sealed so the trans fluid comes out of that one corner and makes little or no mess. By loosening all the bolts equally trans fluid will begin to pour from the edge of the entire pan missing an average size drain pan making a huge mess. If you don't fully understand what I'm saying say so and I'll do up a pic.

Also a razor blade to VERY carefully remove the old gasket. There is an internal gromet that slides around the filter. If you remove the old filter carefully and straight out there shouldn't be a need to replace that gromet. Its a pain in the ass without the proper tools because of the super tight fit in the trans.

you dont flush out a tranny ,just drain and refill with a new gasket and filter.