If the it isn't an AC car, you can reach up in around the back side of the console from the passenger side.
If it's AC equipped, you'll likely have to remove the glovebox to gain access, (open it, remove the door, remove the box out the front), again, by reaching around the back side.
The gauge is held in by two nuts on two studs that are affixed to the gauge that go through a sort of u-shaped bracket that butts up against the backside of the dash, (remove the nuts, the bracket comes off, the gauge pulls out the the front), plus the wires (3 IIRC, being the light, signal and ground) which can be disconnected once the gauge is partially pulled out of the dash.
The big problem you'll run into is if you drop one of the nuts back there as the odds of recovering it are somewhere between slim and none without totally removing the center console.
Actually, if you've ever seen or delt with any kind of aftermarket gauge, it's the same kind of bracket assembly.