What tires require levers, the steel-beaded ones? Been lucky so far can change most fatties and regular ones without levers,the el cheapo plastic ones seem to work alright when unseating the beads, when I was a kid I always ruined the innertubes on the old American bikes with screwdrivers. Got so bad one time tried to wad up newspapers in the tires(didn't work) when you do not have any money you will try a lot of different things.