2003 tundra ltd, six original speakers, any limit on how powerful aftermarket radio to buy?

SOURCE: removing dash of 2003 camry to replace radio

If your dash has not been modified by whomever installed the aftermarket radio, it should go like this:

Using a flat screwdriver, gently pry the bottom edge of the air conditioner control assembly to disengage the clips (there are 6 of them). Pull the control assebly out and disconnect the electrical connectors and set aside.

Remove the 4 bolts on the lower edge of the radio finish panel located under where the air conditioner assembly was located. Pry around the edges of the radio finish panel to disengage the 5 clips (two on either side and one at the top center) The finish panel and radio assembly will then pull out of the dash so the electrical connectors can be disconnected and the radio removed (again, this is providing that no modifications have been made).

Hopefully, you will find the vehicle wiring harnesses and radio mountings still intact. Many times, aftermarket radio installers will cut and splice several of the wires from the original radio connectors, And modify the mountings to accomodate a radio that was not made to fit the vehicle, making it necessary to repair the wiring harnesses and/or mountings before an original-type radio can be reinstalled.