Back-handspring, help please. easy ten points ! :)?

okk, so it's december and i need to get my back-handspring by april-may. i can do pretty much everything else but i need this. i can go into a bridge when i'm sitting down, but it's hard when i'm standing up. how can i do that? after that i will need to be able to do a back kick-over i'd asume, and then my back-handspring. any warmups or tips for me? help please:)