try pressing the trigger then pushing up using the trigger and push up from the bottom (where the pistol grip attaches)

Cause it has to come out since it had to of gotten push in there somehow when they were assembling it :)

Use more force! They're both metal, they can take a bit of abuse.
Maybe you're just not using enough of your girly-muscles :p

Sweeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeet!

I let my mom's friend have a go, he couldn't do it with all his force. We decided to take a hammer to it, smashed the bottom of mechbox where the motor connects and it popped out! I will most likely need to hammer it back in. I guess my mechbox was manufactured a little more tightly to spec.

Thanks for all the help guys! :D