RE: 1993 Camry Heater Core Replacement
The Generation 3 Toyota shop manual shows a simple job.
Remove heater protector -2 clips
Remove heater core -3 screws and 3 clamps
Disconnect heater pipes
The core appears to be in up front under the dash for easy access. Check it out, should know after a few minutes of looking.
There may have a change in the AC system that required taking out the dash, etc when working on the AC condensor.