hello all, i have just started porting my first head and I'm having trouble getting behind the valve guides on the combustion chamber side. It looks like i might have to remove them, the service manual says i need an oil warmer? i don't have one anyways so does anyone no a better way of getting them out, or if i need to at all? the is also a big ridge right under the valve seats with i can remove with removing a small part of the valve seat, and was wandering if someone had any photos of a professionally port and polished 16v big port head i could use as a reference and feel free to share any porting and polishing experiences.
cheers

-hugo