To put on new straps, you can either hammer in or squeeze the straps into the grooves in the grip board. Pressing is the method I prefer (tap the straps a little first with a hammer). Sometimes the grip (radius) curve of the grip board does not match the predetermined dimensions that you can choose from and then you may not be able to get the straps completely against the grip board. To get better results I have modified my tape press from Stewmac. The bars with different radii have been slotted up with a drill and a metal saw to become flexible when pressed. In order for it to work, you need to have a soft but hard material behind the abutment so it can move a bit when you push the straps. This is what it looks like when I push down a tape with the modified tape press.
I choose the counter bar that has the closest curvature (smaller radius) compared to the radius of the grip board. Then the belt ends will be guaranteed to be pressed flat against the board. The counter holds have been fitted with small super magnets to avoid using the screw you otherwise fasten the counter with forcing.
Have tried several different materials to make the abutment flexible, but what I stuck to are regular rubber bands 🙂
The modification gives better results in general and fewer belts have to be changed due to failed assembly.