having difficulty getting left rear one off. I got the left front off. No room down there. Any suggestions?

try one of those adjusting pivoting heads that you can use... i dont know the exact name of it but i use my dads... it tilts so i can bend it in perfectly for the drivers side plugs, they are a pain

Did you remove the air filter components and/or windshield washer bottle (depending on side and model/year) for better access?

If you are talking about the plug wires and they are regular plug wires, just grab the boot as close to the plug as possible, squeeze the boot, twist it, wiggle it left and right, up and down, cuss three or four times and give it a pull. If it separates from the plug connector, well you'll need to replace it but I don't know of any other magic.