the sensor is pretty easy to change, once you find it... it is located on the top side of the transmission, near the firewall... look at the new sensor to get an idea of what you're looking for.

I suggest trying to find one from a junk yard also, as they will usually sell one for $30-$50. Ive changed numerous sensors in 90-93 accords (same setup as a 94 basically) with junk yard sensors and never had another problem with them.

A part like that cannot be found at autozone, its a Honda only part.