big plants, lots of layers of leafs, not enough light!?

so i have a few 5 ft. tall plants and they are really thick and bushy. they have been outdoor all their life and now im transitioning them inside under artificial light (for security reasons) i was going to cut a few clones and off each plant because i im questioning if my lights will be able to supply all of my big boys. is there a way to trim up the plant its self and just thin it out for better light penetration? thanks guys

you could always add some supplemental cfl lighting on the side of your plants if you need to...you could also bend and tie em over, so the light you have reaches the lower part of your plants