1. Remove upper from rifle.
2. With the lower receiver upside down, remove hex head bolt inside grip and SLOWLY lift grip off of receiver.
3. Remove safety selector detent spring and rear takedown pin detent spring.
4. Hold hand over detent holes, turn lower over and catch brass detents when they fall out.
5. With hammer cocked, slide out safety selector.
6. Reinsert safety selector from other side.
7. Turn receiver upside down. Reinstall detent and detent springs.
8. Reinstall pistol grip.
9. Reinstall upper receiver.
Make sure and function check the rifle before any ammo gets loaded. Also, make sure that while you have the upper off, DO NOT let the hammer fly without using your hand to catch it. If it strikes the lower receiver (the bolts not there to stop it), it can and eventually will break something. Avoid dry firing the assembled rifle without a spend casing in the chamber or pulling the bolt off the breech face a little.