by two mechanics. Where are they located, and how do you check if they are bad or not? And someone told me you can repack them with grease? What would you have to get in order to replace them? Thanks

 

What bearings exactly? There are bearings all over your car, and each one is different.

 

Sorry, wheel bearings. Front specifically.

 

They're in the wheel hub. The hub is the thing that is directly behind the rotor. If you've ever replaced CV axles yourself, you have to pull the threaded portion of the axle out through the hub. It's cheapest to pull hub off the car, buy a new bearing on-line (tirerack think carries them $35 or so each), and take to a shop to press them in and out. They're really not serviceable (repack grease). Then get an alignment afterwards if you're worried about messing up your tires...or mark things with a white grease pen...so when you bolt everything back up...it all gets put back together the same.