Here are some suggestions:
- Masking tape + name all the tranny connectors.
- Remove all the loom
remove the firewall plug from the harness and save it... you will want to spray the harness with something to remve it.. personally i use windex as it is slippery then dries up nicely and leaves no gunk.
- buy new loom, dont reuse any of that old crap! Get all the sizes too!
- buy rubber shrinkwrap for everywhere where you have connections, keep it water tight!
- solder everything!
- buy a few rolls of electrical tape and don't be afraid to use it! Buy good stuff (3m) it will last longer
- get wiring diagrams for both!
- pay attention to how they do the loom factory wise... they wrap the cable a few times, then stick the loom on and tape it... it keeps the loom from moving...
- lastly, if it gets overwhelming, take a break or work on something else! Sometimes it takes me a few days of thinking of how to do something, before it finally kicks in.

Other than that... good luck! <img src="/forums/images/graemlins/cheers.gif" alt="" />