* Large 15mm box end wrench or belt tensioner tool.
* Universal Joint for your rachet wrench
* 12-16 inch extension
* Let car completely cool as the nut for the tensioner is on a pathway between the block and the exhaust manifold.
1) Jack up and remove front right wheel. (I always use a jack stand as well, something about a vivid imagination, 12 year old hydraulic jack, and that disk and spindle hovering a few inches over my chest)
2) Remove splash guard (necessary to remove the old belt and fish the new one up around all the pulleys)
3) Put large 15 mm box end wrench on belt tensioner pulley bolt, and rotate clockwise towards you while slipping belt off idler pulley. Release tensioner.
4) Use 15 mm box end wrench to remove idler wheel (Your ratchet might fit, but mine did not, not enough room between fender and nut)
5) Using extension, universal wobble joint, and 15 mm deep socket to get 15mm nut off the old tensioner.
Looking at it, studying it, I didn't think this could be done, but trust me it works.
Because the nut is above the power steering pump, you can not see it. You can barely get your arm up there to feel for it. With the ratchet wrench not attached, you go up through the large middle hole in the metal shield under the car. This is behind the rack and pinion stearing. Follow the only pathway up over the power steering pump between the manifold and the block, and the socket will slip right onto the 15mm nut. Attach the ratchet wrench which is now above the right universal joint boot on the steering arm, and it is easy to turn, because the manifold acts like a second hand and prevents the universal joint from just flopping around.
AND GOOD LUCK! Don't ya just love those automobile engineers!!