Sometimes a baffle can be difficult to remove.
Usually twisting back and forth and moving in and out will free it up for removal. Be aware that the removal pin can be bent broken out of the baffle.
Darrin Kong has offered an alternative for stubborn cases:
If you have a stuck/stubborn Triple baffle that you need to remove from the muffler, upon a suggestion of Porschedave from the K2S forum, I utilized a slide hammer. In the case of my 69 H1 muffler, I simply used the supplied pair of hooks and 2-way cross block, but mounted one of the hooks on the OUTSIDE of just ONE side of the block in order to effectively fit into the baffle end and hook underneath the baffle crossbar.
While you hold the muffler securely or better yet while it is still mounted to the bike, make sure the hooks are both evenly resting underneath the baffle crossbar so that the load is evenly distributed to prevent damage to that crossbar, and then pull on the slide hammer weight until the baffle comes out.