How do I remove them, tried a pick at the joint but no luck.

Thanks.

Are you trying to eliminate them or replace them

When I decided to remove the O rings from my block I wanted to fill the grooves so I would have a good flat surface. I finally decided to use a large mill file and very carefully filed the rings down to block level. When finished you could not tell where the O rings were. This was several years ago and they still look great. Wouldn't hesitate to do it again.

Remove them. I'm planning on running a Fel-Pro 1008 gasket and don't need the o rings. Also I plan on having the deck fly cut to ensure they're flat.

File them flush so it fills the groove

Will it cause any problems when milling the block?

Let them mill it off

I have used a small pointed punch to start the O ring to back up from the joint, tap gently and once the wire is making a V or U grab it and pull it out from there IHTHs