I just replaced my Power Steering pump last weekend. It was not on an Explorer, but a 94 Aerostar 4WD. Same 4.0 as the Explorer. The pump had been whining very loud since I bought the van in November. I had never replaced one before so I was a little hesitant about doing it, but I couldn't stand that noise anymore. It was very easy. You do not have to remove the AC compressor. Unscrew the high presure line, and slide off the return line (very easy) Remove the Pulley after you take the belt off of course (5 minutes to remove the belt) and then remove the 3 bolts holding the pump on. Then the pump just drops right out and came out through the top. If I was able to bring the pump out through the top on this Aerostar you Explorer guys should not have a problem at all! I bought a remanufactured pump at autozone with a lifetime warranty for 60.00 bucks. They let me use there pulley remover and pulley replacer for a 40.00 deposit which I got back later that afternoon. You do have to bleed the air out of the pump before you start the motor. I decided to bleed mine with the front wheels off the ground, which is something I had read about. Anyway the pump came with bleeding instructions. Just do what it says. After I finished I fired it up, and I was totally shocked how quiet it was. When I turn the wheel I can barely here the pump working at all. I can actually here the motor run now, and not that pump!