Where did you get the spare/new LED PCB? You can just buy ones that have the switches on either end?
I'm not sure if you are kidding?
I reverse engineered the circuit boards, redesigned for the desired displays, laid out a board in the cad package, spec'd and ordered parts, sent the PCB out for manufacturing then assembled when I got it all back. That covers the first try
-edit: left out stuff about SAFELY disassembling original boards, sourcing bezel materials, routing to correct dimensions...