Toyota Celica 1990-1993 Stereo Head Unit Removal

Pictures are from 1991 Celica Alltrac ST185, but apply to ST, GT, and GT-S  from 1990-1993 as well.
Click on image to enlarge.

1) First, it is a good idea to disconnect your battery.
2) Remove a plastic piece surrounding shift boot. There are four clips located at its corners. Use a small flat head screw driver to pry it UP. I suggest you to start from the lower right or left corner.
 

3) Remove radio bezel. Once you remove the shift boot surrounding piece, remove the ash tray and remove the bezel by unscrewing two Phillips head screws at the bottom of the bezel. Then pry the bezel out using a flat head screw driver. Be sure to force the bezel DOWN and OUT, (NOT left and right)
 

4) Now, you will see four screws holding the head unit. Take them off and pull the unit out of the console. Done.  
 

 Please note that this information is based on my personal experience. It's up to you to follow it or not. I will not be responsible for any kinds of damages due to following this information. :-)