Valve cover spark plug gaskets stuck, any advice?

Hey guys, I am replacing the valve cover gaskets on my 1996 tacoma 3.4 and all was going smoothly until I tried removing the spark plug gaskets, they are as brittle as can be.
What should I do?

 

You will have to keep working them with a punch until you can bend them enough to grab an edge with pliers then pull it out. That is what I had to do with mine.

Be careful not to scar the surface too bad when trying to get it out.

 

ended up using a chisel to fold the sides down, it actually worked really well