I am attempting to replace the upper forestay and the ib halyard on a late 70's H-16. It looks like I will have to replace the block that connects the upper and lower forestay together and what the halyard runs through. There seems to be no way to take this block apart to release the old forestays. I would like to be able to reuse the block and don't need a new forestay. Anybody have an advice?

You can drill out the original flair pin and replace with a clevis pin and cotter key.