i need to remove caps from new copper water supply for kitchen sink so i can install shutoff valves how do i do that?

All you have to do is, shut off the main supply from inside the house. With a plumber s torch heat the copper caps and when the solder starts dripping pull them out with a channel locks. After, make sure the outside, the edge and the inside are 100% clean. Sand them with a wife brush or sand paper. When everything is 100% clean ( it is very important that you have clean surfaces for solder to fuse at the first shot), stuff about half inch of the  copper pipes with bread, paste the outside of the copper pipes with flux, put the shut off's in place, warm the copper wire properly and feed the solder. The bread helps to dry any water that might be trapped there. When done make sure you let the water run for a while cause you would be washing your face with bread paste.

thanks it worked

First of all  you have to Shutting Off the Water Supply and then Disconnect the Water Feed Lines and then use basin wrench that have two nuts, placed both nuts nuts on caps and then scrape off. This is the easiest way to remove caps.

I have no knowledge regarding the question you asked but  i can say that your question and the response you get will be helpful for me in my future whenever i got stuck in such situation. Thanks for questioning.