I went ahead and did it. Ive got a 00 4.0 SOHC and it was a lot harder to do this than on my mustang. THe mustang has a rubber tube that you just pull out with barely any force. On the explorer i had to unhook the MAF and then take the air assembly cover off and the air filter too (which by the way i substituted with my first mod-KN filter). Then inside there is this hard plastic tube (silenvcer) which is a bit tricky to get out. You have to pull it out of the air assembly toward the lights and then fidget with it until you can pull it up and out of the car. What I did was stick a screwdriver inbetween the tube (the side outside of the airbox) and the airbox (when you look in there you'll know what i mean). and sort of just pushed it back and firth until it popped out. Then I sort of moved some of the cables around until i could get it out of the assembly. I guess you could also take out the assembly but i didnt want to do that.
PS-once you take the air filter out, the silencer is the only thing in there, you cant miss it, if you have it. With the silencer out and the KN in I did feel a difference. I was able to get higher RPM readings before the automatic shifted. I felt like i gained more HP, and the noise was nice too.