The easiest way would be to find and transplant an engine/manual transaxle from a donor car, including the ECM and harnesses. Maybe you can even make a deal with the local salvage yard to trade in your working engine/tranny. The Celica or Camry combo should work, but stay in the 1997-1999 year range if possible.
However, as you know, take note of the donor car's mileage and age (they track this info in their computers, but an eyeball on the dash helps)so you can get an idea of the condition of the "new" combo. Since it's out of the car, now's the right time to replace any worn parts: clutch, fork, throwout bearing, flywheel, etc.
Welcome to AF and let us know how it goes!