Hi mate, it's quite an easy job to do if you have a little bit of mechanical know-how. I had to do it myself recently. Firstly, you have to remove the upper timing belt cover(some of the lower bolts can be difficult to get at, go through the driver's side wheel arch and remove the splash-guard at the front thats held on with 2 small bolts, you'll need to do this for later anyway)which requires removing the dog-bone upper engine mount. Once you've got the timing belt cover off, immediately put a small paint mark on the cam gears and belt, just in case the belt slips while your working, so you'll know exactly what tooth goes where. The upper idler pulley is right in the middle of the cylinder Vee and can come out now with a 14mm socket. To get the new one on you'll have to remove the hydraulic tensioner located at the rear of the engine, just above the sump, it's a small silver tube-like device pointing straight down, about 10cm long and attached with 2 12mm bolts. Before removing it, place a small nail or allen key into the hole in the rubber grommet on the tensioner to lock the piston in place. This will make re-installation much easier. Now you can put a long spanner or socket wrench onto the rear cylinder bank cam gear and turn it clockwise just enough to get enough slack in the belt to re-install the idler pulley. Re-assembly is the opposite, do the tensioner(slowly "walk" the tensioner in by alternating between the 2 bolts), pull out the nail or allen key(may need pliers), re-install the timing belt cover, dog-bone mount, and inner wheel-arch splash guard and you're done. Oh, and get the pulley from a bearing place like CBC, same pulley just half the price Toyota will try to charge! All the best, any problems PM me.