Spoke puncturing my tube, can I cut it?
I'd cut it without a special tool:


fully unthread the nipple
remove spoke from the rim (no need to remove it from hub)
fully thread the nipple as far as it can go
cut 5mm of spoke thread with a regular cutting plier
fully unthread the nipple. mushed threads (from the cheap pliers) will be fixed that way
insert spoke into rim
thread nipple as much as necessary


Other options:


simply remove spoke from rim until you get a shorter one. missing 1 spoke doesn't cause any problems
partially unthread spoke and bend it in the middle with pliers until you get a shorter one
leave spoke as is and place a rubber square from an old tyre between spoke and rim tape to prevent any further punctures