How do i replace a wheel bearing 1998 cavalier

OK. Jack the car up and put it on jackstands!!!
Tools:
sockets
ratchet
wrenches
ball joint removal tool (a.k.a.: pickle fork)
hammer
checkbook/ credit card/ bank card
friend with a car or another vehicle

I find the best and cheapest way is to buy the bearing and seal(s) and have a shop press it out and in. The bearing and seal(s) are under $100 and the labor for pressing is about $100. If you take it to a shop, it's usually about $500 to $1200 depending.

1) Pull off the wheel and tire
2) Find a socket big enough to take off the cv shaft spindle bolt, and remove the nut(it should be the really big nut in the center of the brake rotor.) you might need help from someone to step on the brakes to keep the wheel from turning. If you can't find anyone, put a prybar between two lug studs and the ground (kinda like playing tic-tac-toe with two studs and the ground)
3) Take off the cotter pin for both the tye rod end (the part that goes into the rack and pinion and makes the wheels turn) and the lower ball joint. You might have to get on the ground to see it.
4) Take off the nuts for the tye rod end and the lower ball joint.

(***Point of no return***: If you don't feel comfortable doing this, stop now and take it to a shop)(or call a friend that knows how to do this) (You will potentially messing with the alignment of the vehicle, maybe)

5) Take the pickle fork and place it between the rubber boot and the steering hub assembly. Tap it with a hammer till it's snug. Now, start hitting the pickle fork till the ball joint pops out. If you get to a point where it's not budging, start stepping on it. Put your weight on it to see if that will pop it loose. (Keep one hand on the car for stability- hence the reason for jack stands.)
6) Repeat the process for the lower control arm.
7) Pull straight up on the steering hub to free it from the lower ball joint. DO NOT pull it away from the car too far or you'll run the risk of damaging the cv shaft bearings or boots.
8) take a hammer and tap the cv shaft spindle to drive it thru the steering hub assembly towards the center of the car.
9) Unbolt it from the strut. there should only be 2 bolts with nuts. Don't worry, with the car off the ground, there should not be any pressure on the strut.

With the whole steering hub assembly off, go to the auto parts store and purchase a new bearing and bearing seal(s). The best place to have the bearing pressed out is usually a tire house like Goodyear, Firestone or Les Schwab if they have the press. Some autoparts places also have machine/press shops that would do it.

10) now with the whole assembly back. Reverse the process to get it back together. It usually goes faster than you realize.

NOTE: Now that you messed with the alignment, it probably wouldn't hurt to go have the alignment checked out. If you have any other questions with this, repost and I'll do my best to figure it out. Hope this isn't too overwhelming.....