Just pull out the old internal parts and slip in the new. There is a little "T" shaped part rivited on the right hand side of the rifle that holds in the pins. You have to push down on the end of the "T" cloest to the muzzle. It will tilt and you can remove the pins from the trigger and sear assemblies. Then you'll see a small screw in the top of the big piece of metal that's welded in there. Use a small allen key to remove the screw. That will allow you to pull out the selector and finally the sear spring.
Replace all parts with new ones from the kit. You may have to use a dremel or a hacksaw to remove the extra "leaf" from the new sear spring. Just use the old one as an example. I replaced my bold carrier, dust cover and springs too, though it probably wasn't nessasary. DO NOT REPLACE THE BOLT!!!!!!
Any other questions feel free to PM.
