For the 2003-2004 seat model, see the following pictures.
You will only have to connect motors and battery to the freshly cut switch cable, as shown in the last image.
Mathew, thank you for this site.

It appears the switches are the same.
Yes, you can do it.
R1+, R1- will go to Motor 1,
R2+, R2- will go to motor 2 and so on.
All you need is to provide 12V on 30 and 31 and make sure you have + and - in an "X" pattern for each switch.