what to do about outlet in bad location
There's no easy fix here.  The electrical code is quite clear on this, and the box must be "accessible".  Hiding the box behind permanently installed cabinets is a clear code violation, even if you cap the wires and install a blank plate.

You'll have to find where the wiring for this receptacle originates, and disconnect it at that point. Cap those wires together and label them as abandoned, or pull them out of the box so they can't be reconnected. Once that's done, you can leave the unused cable in the wall and abandon the box. 

If the abandoned box was used to feed outlets further along the circuit, you're going to have to find a way to run new cable to supply the rest of the circuit.