its in the middle dash behind the console, remove the console, and just start at the bottom by removing every small bolt you see till you see a heater core, (there's a few layers of stuff, and there's a bolt holding the core to the fire wall where the tubes exit) your back will hurt from having to lay in all sorts of messed up positions, but it can be done in an hour or so, did mine, sucked, but its done.
tools needed:
nut driver, with very small sockets
a flash light
maybe a small pillow to hold your head in some of the messed up positions you will be in
