Front wheel bearings on a 4 wheel drive Explorer are not serviceable, replace them.
Yes the rear bearings are replaceable . Bearings and the races are very easy to replace or repack , It may have a castle nut with a cotter pin or a crush nut , if it has a crush nut you may want to order a new one before you take it apart .
An easy way to do it is to put some wheel bearing grease in the palm of your hand and then, scoop up the grease with the end of the wheel bearing. You will see the excess grease come out from between the bearings. There's an instructional video included below also, that shows how to replace these on a 93-97 Ford Ranger.
specs on how to replace a heatercore on a 1993 ford explorer
You will have to replace it. The bearings are worn out in the blower motor.
It has 1 big hub bearing per side and you can not service them. It has factory sealed bearings. If there bad then you must replace the bearing.
The fuel tank will have to be removed from the Explorer. The pump is bolted in the top of the tank.
Bad bearings in the alternator. Best to just go ahead and replace it.
If you need to ask on here, then you shouldn't be doing it yourself. Take your car to a garage.
Someone else has answered this here: http://www.faqfarm.com/Q/Where_is_the_fuel_filter_located_on_a_1993_Ford_Explorer_Sport
loosen the clamp holding the hose on to a fitting and pull the hose free.
A 1993 Ford Explorer has shock absorbers , front and rear
The front wheel bearing need to be pressed by a press. Unless you have a press, I suggest you take it to a shop that has one and have them do it. The bearings can be found at autozone, or advance auto cheaper than any garage can find them for.