Puncture Repair is a Myth

you can do it without levers if you have the right tyres. some tyres you can easily remove by hand. then you let the tyre slide to the side, take the inner tube off, pump it up as 31trum says and find dat snakebite or whatever. patch it up. put the tube back on and fit the tyre as before. however you're a bit lost without levers because a lot of tyres are a bastard to get on and off by hand..

I have never had a problem getting any tire off without a lever, never ever ever.

Ever.

The trick is to slide both beads into the recessed centre 'well' (or dip) and then work the tire from one side, stretching it until you can pull off the opposite side, I can get pretty much any tire off in a minute or so without levers.