1. First, according to the shape to be cut, make a template with the same cross section as the square pipe with cardboard or other materials.

2. Secondly, tap the pipe gently with a hammer or other tools at the position to be cut, leaving a cutting line, and cut along the cutting line with a metal cutter, steel scissors or other tools.

3. Finally, the position of the incision is polished and trimmed to ensure that the incision is smooth and smooth, and there are no burrs at the corners.