Yep, I have removed them before when my bronco II had its original engine. There is a little thing(I dont know what its called) that screws into the spark plug hole and lets you fill the cylinder with compressed air, so the valves wont fall in. I have also heard of using 1/4" rope and pushing it in the spark plug hole. You then turn the engine over by hand until it wont go anymore.
Now...the thing is is that I have some lifter noise...When I changed my cam the instructions said dont use dual valve springs, but I figures that with roller rockers I could get away with it...I donno....maybe too much valve spring pressure for the lifters to keep up with?...I am going to give it a few days, then I may take it apart to adjust the lifters again, but if that dosent work I will need to change them to a stock style spring