Block Heater Install Tips?

I’m trying to install a freeze plug type block heater in a '95 Chevy K1500 and am having some problems getting access to the freeze plug to hit it out. It’s on the drivers side, rear right behind the oil filter. When I changed the oil last week I tried to get a screwdriver and hammer into the area of the freeze plug but couldn’t get enough leverage to drive the plug out. I hit it with PB blaster thinking it might help break free all the crud but not luck. Any tips? Would a punch make that much of a difference? I was laying on the ground attempting this, any other angle to approach this?
I hate to take into a shop for such an easy project (I’ve called and got prices ranging from $75-$250 (chevy dealership quoted me $250-500!). Or is there another freeze plug that would be easier to access?