I need to replace the anchor pulley as it is worn through and I purchases a new Delron one. However, I cant figure out how to remove the old one. There appears to be no room to remove the old pulley and the metal bracket in welded to the main assembly. Any thoughts? Thanks.

You will have to take the platform off in order to get the bolt holding the pulley out.

No, just take off the teak platform from the bowsprit.  It is held on with long threaded rods going thru both sides of the platform and the bowsprit.  Try getting one side off by removing the nuts on that side, and forcing the teak to move outboard.  You could possibly force both sides partway off, just enough to get the bolts holding the anchor roller frame off.