valve replacement

[vacnsewmedic]

I here this is pretty simple and not that expensive, Im keeping it cheap because the engine only has 75,000 miles and the chain broke and bent the valves on 1 & 2 (no compression) 3 & 4 are reading 150 basically, I was told by an mechanic that the head is still good (lifters)and all u need to do is pop the exhaust valves in and thats it ( im going to get the head done anyways but do i really have to and if someone can give me a small amount of advice or direction when doing this type of job?

thanks