[Yannos]

I never used a Glock but I would do that:
Remove Mag from glock,
Rack and lock see if there is a BB in the chamber, if so use a cleaning rod to push BB out.
Bring the slide back home,
Aim at a safe direction,
Press trigger.

Thats what I would do.. like I said I Never used a Glock before so someone might have a different way!

EDIT: shit too slow lol.