It can be done with the motor in the car. For the pan gasket, put a jack under the motor. remove the front motor mount, place a couple short 2X4's under the harmonic balancer and lower the motor down - you want the balancer to rest on the blocks to support the motor. Then you can remove the pan. Replace the gasket and reverse to assemble.
I think you can pull the balancer and replace the seal without removing the motor. Remove the passenger rear tire and the splash mat. I have done it but I removed the 2 rear cradle bolts and let the cradle tilt about 2 inches to give me more room to work. I did the front seal in about an hour.
