How do i make my crusting butter cream really crust, mine always remain slightly crusted but still melts. I put the cake in the freezer to crumb coat then i remove it and put on the remainder of the butter cream and it just dont get all the way crusted. please help, thanks

Add more powdered sugar, it will crust faster.

What are you using to make it ?

If you are frosting a cake out of the freezer, it's probably condensation that's preventing it from crusting properly.  Try on a room temperature cake and see if it works out.  If yes, then problem solved.  If no, then your frosting recipe needs tweaking (more sugar as suggested).