AutoZone sells a spark plug socket with a built-in swivel. That's probably the best tool I've bought.
It can be done from the top, but it's insanely easier through the wheelwells. Taking the wheels off gives you more room to work, but it's not too bad even with the wheels on, if you jack it up. Changing them from the top is a lot easier on an N/A S-10 without A/C, but #3 still sucks...