[1] Place your front side-up on a flat surface that will not be damaged if you use a hammer on its surface.

[2] Unzip the fly and open the waistband, find the hole of the previous button and insert the track on the backside of the hole, with the flat area placed to the inner side of the pants.

[3] Place a flat work area under the track, be careful as it can leave a mark on the surface.

[4] Holding the tack in place from behind, place the button on top of the tack (you can take them carefully with your fingers or use a pair of pliers to hold the button in place)

[5] Hammer the button onto the tack, with a straight downward pound.