Duplo wheel removal tool

I wanted to replace the wheels on some Duplo carts but had great difficulty getting the original wheels off without damage. In the end I came up with this idea which is simply two custom made wedges which are pushed between the wheel and the cart to force the wheel off.

To use, simply position the wedges as shown in the photo (smooth side up) and push them together until they meet. With a bit of encouragement and a twist, the wheel should then pop off the end of the axle.