If you dont have a jack or the tools they can be found on eBay pretty cheap.
If youve never owned a Toyota and dont have a manual, I would imagine it would be a mind puzzle to figure out. I found this info on wikianswers:
Locate your tire changing tools...there should be a rod with a rounded hook on the end, and a turning handle to attach to the other end.
Now, go to the back of the truck. In the center (either in the bumper itself or in the body), there is a slotted-shaped hole. Attach the turning handle to the end of the rod, and insert the rod, hook-end first. The curve of the hook needs to mate up with the winch inside the hole (you may need to look in the hole with a flashlight first to see what you're aiming at). Once you've got the hook locked into the winch, just start cranking down and the spare tire will lower to the ground. Once you have it on the ground, you can take the chain out of the middle of the wheel.
You can put the other wheel back on the chain and wind it back up again if needed.