Sundance Hot Tub Circuit Board?

I am having trouble putting the wire from the circulation pump into the terminal block on the circuit board. I push down and back on the plastic tab but it does not open the jaws. Is there an alternate method i.e. prying open the jaws with a screwdriver, using a sheet metal screw to srcew into the terminal block. The board is 13 years old so that me be part of the problem. I tried other terminals on the block and have the same issue. Parts: Sundance Optima 1998 Board 6600-028