I successfully finished the job last week. It it weren't for the excellent resources online, this would have not been possible. Huge thanks to
Shipkiller for the incredible instructions. As expected the OEM motor was soaking wet and corroded. I am extremely happy with the replacement Mustang motor. It is very fast at opening and closing, and was a fraction of the cost of the BMW part. It even came with a bracket to mount it on. Relocating to the motor to the trunk was very simple, and did not require any additional wiring or extensions. My replacement motor/pump already had plenty of hydraulic fluid in the tank, so I did not need to add.
Just to correct the original post, reversing the positive and negative terminals on the motor, will either cause the top to open or close. Not reversing the hydraulic lines. So if you press the open button and the top closes, just reverse the positive and negative terminals.
If anyone has any questions, I would be happy to help.
