When removing a tire, at the point where you first get the lever to pop the bead over the rim, if you apply direct pressure with your hand to the tire at that spot, it increases slack and makes it easier to continue sliding the lever under the bead. I rarely need more than one lever to get a tire off (only if the rubber's really old and got a bit "glued" into place at the bead seat). Also, always pump a small amount of air into the tube before seating the second bead on the tire; failure to do so can cause the bead on the new tire to snakebite the tube after the tire's completely installed.

Nicely done series of photos and instructions.