Toyota Repair: Check engine light, fluid contamination, celica gt

Question
I have a 1997 celica GT 2.2. I hooked up the diagnostic computer and it came up with the PO773 code. After looking around it seems that this is the tranny solenoid, or E electrical sensor. How easy is it to replace that sensor? Also, from what I was reading, will that even help the problem or is my tranny on it's way out?

Answer
Most of the time the solenoid is not the problem but rather the result of fluid contamination clogging the opening of the solenoid, I would recommend removing the transmission oil pan to check for any metal particles or transmission clutch material in the bottom of the oil pan. If the fluid looks dark/burned and there is metal or other material in the oil don't spend any money on this transmission it will have to be replaced.