What Ian rauk says. Valve bit first then make sure the bead of the tyre is in the well in the centre of the wheel. Push the tyre over the rim as far as it will go then go back to the opposite side and push the bead of the tyre into the well of the wheel and work your way back round and force a bit more of the bead over the rim. You may need to go through this process 2,3,4 times depending how tight the tyre is. There is a video on youtube somewhere showing you the technique. Follow this technique and you will never need tyre levers to put a tyre on.