Disassembly 

1) Place selector lever on SAFE
 
2) Remove magazine by pressing magazine release button (see fig. below)

 
3) Open bolt and eyeball chamber.

4) Remove sling

5) Push supporter of recoil spring assembly into receiver and pivot upper receiver from lower receiver (see fig. below).

6) Remove recoil spring assembly

7) Pull charging handle all the way back and remove it.(see fig. below)

8) Remove bolt carrier and bolt

9) Remove gas regulator

10) Push receiver pivot pin (see fig. below).

11) Separate upper and lower receivers

12) Remove handguards

13) Remove firing pin retaining pin (see fig. below).

14) Put bolt assembly in locked position (see fig. below).

15) Remove firing pin through rear of bolt carrier (see fig. below)

16) Remove bolt cam pin (see fig. below)

17) Remove bolt assembly from carrier

18) Remove extractor pin (see fig. below)

19) Remove extractor (see fig. below)