Do I need to remove or prep the spark plug wire before wrapping?

Yes — disconnect the wire from the plug cap first. Wipe the wire clean of any oil or residue so the wrap sits flush and makes full contact. You can reinstall and reconnect after the wrap is in place.

Does this wrap slip over the wire or does it need to be fastened with tape or clips?

The wrap is designed to slip over the wire and boot. Test-fit it first to confirm your wire diameter matches the 6" opening — if it's loose, you may want to secure it with high-temperature tape or a small zip tie to keep it from sliding.

Can I use this on multiple wires, or do I need one wrap per plug?

One wrap covers one spark plug and its boot area. If you have 4, 6, or 8 cylinders, you'll need multiple wraps — plan for one per plug wire you want to protect.