just to let you know the VFC scar L is a version 2 gearbox. and its accually quite easy to remove the gearbox and open it up. Phil is right with the selector gears on the inside of the lower but if you follow the guide you will have no issues reinstalling the selector switch group. I have a VFC scar H and have opened it and about 10 other scars in my time working as a part time gun doc here in london. again its not too hard to do if you are in any way shape or form a handy guy. again follow the guide and dont worry about messing something up. everything can be repaired or replaced if you break something.
Full Auto= WIN!!!