compustar cm6300 to cm6000

Hi everyone, thanks for reading.  Just wonding if anyone with experence upgrading a CM6300 (alarm only) to a CM6000 ( alarm w/ remote start).  I had the CM6300 installed professionally.  I just want to get an idea of what is all involved. This is for a 2003 Vw GTI, I do have a immobilizer but I am working on deactivating that via Vag-Com, or programing my own chip since the stealership wants WAY to much to program a key.  Lets say I deactivated the immobilizer, would everything be plug and play from the old brain, it sounds like it is..?  I guess my question is:besides programing the brain (tach, etc) and doing a immo bypass, what else really is there that would need to be done?  I was orginally just going to take it back but they want $350 to add remote start, and I really can't imagine a whole lot needing to be done to add it.  I am mechanically inclined and I know how to solder wires and read a wiring diagram, and I have the compustar installer manual.   Thanks you so much for taking the time to help.

The main power connector is different and would have to be changed. Its the harness that goes to the ignition wiring. The rest depends on the original install. I kinda doubt they hooked up the tach wire or foot break wire on the original install for an alarm only, but they may have. you will just have to go down the wiring guide and see what has been wired up and what has not. At the very least a considerable amount of the work has already been done and the harnesses should interchange. You can also use your remote and antenna just program them to the new brain.

Thanks very much!!