Hi, Sandman,
I am not sure what you are trying to do. Is there a law in your area requiring that you remove the bayonet lug? If so, it would be better to cut off just the lug or weld it up so a bayonet cannot be attached. The bayonet lug on those rifles is part of a nose cap that is closely fitted to the wood. If you remove it, and then try to put the upper band back on, there will be an unsightly gap.
If you are going to cut the stock for sporterizing, that is usually done further back.
Once you remove the cross pin, you should be able to get the nose cap off, using POBF (plain old brute force). Clamp the lug in a good vise and then pull the stock off it. It is not easy, but it will come. A rubber mallet at the pistol grip may be needed.
BUT, if you are one of those guys who just has to take a gun down to the tiniest part for the helluvit, can I recommend you forget removing that part? I can't see any possible reason to do so.
Jim