Ive got an 04 x-type AWD that has the 3.0L. I have to change the oilpan gasket and due a tune up on it. Everything ive read about the gasket is I have to drop the trans. My question really is can I swap in a standard trans for the automatic? Is this even an option? Mechanically im pretty good. Also what changes with the computer will need to be made? Or can I swap computers from the doner car? Any advice would be great thanks

 

You don't have to remove the gearbox to change oil pan gasket. You have to remove transfer case or drill a hole in it.
As for changing from auto to manual you have to do a lot of work, just changing trans ain't gonna to it. You need clutch pedal with master cylinder, different brake fluid container, all the lines for clutch, manual shifter with shifting cables that are not easy to change, clutch pedal switch and wiring and of course manual gearbox with clutch and flywheel. As for ECM, I think it would work if you change the wiring a little (need to change anyway), but not 100% sure. If you end up using different ECM then you need a dealer or someone to program it to your car.