3 mounts. The easiest is the #3 passenger side. Lift hood, look by the belts for the odd looking object holding up the engine. Bolts on the top side of the frame and side of the block. The part holding the block should be centered inside the part mounted to the frame. If it looks low or if there is cracked rubber or discolored rubber from fluid leakage, it has failed. If your car vibrates or makes knocking noises at weird times, start by examining the mounts, esp this one. The next one supports the trans at the back below the exhaust. Not sure what it looks like when its bad. The last one is under the battery. Just about every piece of plastic has to come out to get to it...and the ECU pod as well. Not kidding - I felt like Mary Poppins and the engine bay was her bag! Stuff just kept coming out and out and out! When diagnosing engine mounts, again thing is vibrations. All 3 of mine had failed by 70K/8 years. I only knew b/c of vibes. Different areas, sometime felt like a CV, sometimes under the body, sometimes felt like a control arm or swaybar. Again, vibes or knocking. That's the big clue.
Dont forget those strut mounts in the strut towers in the engine bay. As I already said, I thought mine were good, but 10K later, one was bad. I will have to tear it all apart to replace it. Probably gonna live with it until the KYB GR2 fails and it has to come out anyway. Don't be me.