How to install access bed light?

I know this is probably really simple, but I have absolutely no experience as far as electronics go. I got a access LED light strip as a free gift from AutoAnything when I ordered an access roll up tonneau (that installation went smoothly). I really want to put the light in and don't need to control it from the cab, but from the button that is connected to the strip. It requires connection to a 12 volt power source and ground wire, not sure where those are located in a TRD taco. Any help is appreciated, pictures would be great.

 

You can get a fuse tap or add a fuse and plug that in under the dash in the fusebox to a port that turns on with ignition, then run the wire from there, through the firewall, and back to the positive wire on the light. The negative wire on the light can be grounded to any bolt that is also somehow grounded to the frame (which is just about all of them). There may be a constant 12v source that is closer but someone else would need to chime in.

 

Alright thanks, I think I'll try it next weekend.