I gave it a shot. I thought I had it but once I powered up the Uno board via USB, the power light comes on very dim then shuts off.
I switched the two legs on the pot, +5 and ground, but I don't think you can hook them up backwards, the two outside legs. They can be connected either way, right? I have One outside leg to 18, the other to 20 of the LCD. LCD pin 3 is connected to the center leg of the pot.