Sayco diverter stem broken, can't remove last bit

[surfboarder]

This is from an old 3 valve installation. I'ver been unable to remove the last bit of the old stem. I think there is some corrosion built up on the remnant piece, which prevents it from backing out through a passage about 3/8" diam. - which, obviously, at one point it fit through Any suggestions?

[isaacvs]

I have no idea. If it won't come out, you may just have to replace the whole valve body.