Help with Rhino…

Ok so I’ve been given a primed space marine (yuk) think. Managed to prise the top doors off, but side doors don’t seem to want to play ball. Is there a relatively easy way I can make this world eaters? The WE doors on eBay are like £10 each, may as well buy a chaos rhino if I’m spending that?

I’m 2 months into my WE/40k obsession, so I’m a noob, help me get Khorne his skulls please! 💀