Pliers or a hammer, combination wrench 10mm & 13mm, Allen wrench 2.5mm & 5.0mm.

1.Remove the old punching pin set

1.1 Disassemble the screw nut on the central joint with the combination wrench 13mm and the screw nut on the left handle with the wrench 10m, then you can take the head part away and the punching pin & the spring will fall apart. 

1.2Remove the screw with Allan wrench 2.5mm

1.3Put the old punching pin inside the upper hole from the other side and hit it with a hammer to knock down the upper mold

2.Install the new punching pin set

2.1Lay the upper mold between the jaws and align it with the upper hole, then use the new punching pin to push it into the upper hole, and hit the punching pin with a hammer to ensure the upper mold totally into the upper hole, finally fasten the upper mold with the screw. 

Attention：Just fasten the screw, do NOT tighten it over, or it will affect the concentricity and lead to stuck. 

2.2Install the new punching pin & spring.

2.3Fasten the screws on the central joint & on the left handle.