Using the Jokari wire stripper is easy. First, select the appropriate blade for your 7.5 to 9 mm Ø round cable. Open the stripper and place the cable section you want to de - insulate inside. Close the tool gently and apply a bit of pressure to strip the insulation. When working in tight spaces like cable ducts, hold the tool firmly to ensure precision. For blade changing, use the exchangeable cassette system. Just remove the old cassette and insert the new one. As for maintenance, keep the tool clean after each use. Wipe off any debris or dust. Store it in a dry place to prevent rusting. Avoid using excessive force as it might damage the blades or the tool itself.