Small blades for the shaver are crafted economically from a regular safety razor blade.
Use a utility scissor to cut the blade to about the following size. Depending on ear size and user competence, the blade can be smaller or larger. For beginners I recommend the following size.
Mini Blade, approximate width and height: 3/8 by 1/8", 9 by 4mm
Secure the blade by pushing it firmly into the shaver's slot by use of an edge, such as a piece of wood.
Adjust and/or remove the blade by firmly pushing it against a sold edge.