if the foot is glued to a rock and i rip it out will it die if so how do i get it to move

are you asking if you can remove the ROCK? or remove the clam and not the rock?

Yes it will die if you just rip it off it tears the foot of the clam. I have heard you can aim a power head at it and it might encourage it to move

Two options:

1. Do something (power head pointed at it etc) to make it release

2. gently and carefully cut the foot as close to the rock as possible with as sharp a knife as possible

Do NOT cut the foot! Cut the byssal threads which bind the clam to the substrate/rock. I have successfully done this several times in the past. HOWEVER, if the clam is held bang against the rock and you cannot get a sharp knife under it to ct the threads then dont try it. You will kill the clam. Do Urchinhead says and aim a powerhead etc. It might take days or week or wont move at all.