I just cleaned mine out last month. I had to cut a new one out from a gasket package (it came with sheets of cork, paper, rubber, etc..) I used one for fuel applications and it is still holding...

If you plan to re-use the existing one, be very carefull taking it apart. It is steel but mine was like lots and lots of super-thin layers of steel and it separated at a few places between these layers and I couldn't re-use it. Part of it came off with the EGR and some of it stayed on the manifold.

Maybe try to pry it lightly all around first before pulling off the EGR.

Good Luck!