I just recently replaced the sub in my '99 Explorer. Mine was an 8" sub which was attached to the enclosure with a bolt going directly into the back of the magnet. If yours is the same as mine then you will have to pull off the rear plastic panel, or at least pull it mostly off, in order to pull out the entire enclosure. I then popped in an 8" Sony Xplode sub which has worked quite nicely for me. I did have to make some rubber gaskets just for spacing purposes though because the Sony is about 1/4" too deep for the enlosure. This was the best option that I could find after a few days searching. Hope that helps.