Does anyone know how to get into a cupboard?

I can still smell catty-drugs (Catnip! mmmm) coming from the cupboard where daddy put the weird thing, wrapped up in red paper, for me.

I keep trying to paw open this cupboard, but I can't get in :(
I have tried nosing it open too, and simply miaowing at it, but this doesn't seem to work.
Any ideas?