How do you change the PCV valve on a 1991 Toyota pickup 4 cylinder?

Remove the vacuum line connected to it, (top center of valve cover - vacuum line connects to intake manifold). Roll a rag and place it next to the valve, using a pair of pliers pry up on the valve using the rag as a fulcrum. When removed from the grommet, use the pliers to remove the grommet from the valve cover and replace both.