The fundamental question here should be "Is there an solid reason to remove it?"

Unless the cable guide is broken or worn through, there's no reason to remove the bolt in the first place. Of course, it might get worse over time, but you may never live to where it's actually necessary to remove the bolt and replace the cable guide.

However, if you must remove it, you have a few choices, the simplest being drilling in through with a 3mm or smaller drill, then using an easy out on the remaining tube, or enlarging that to 4mm, and trying to retap. Or you can drill it out totally and use a blind rivet or glue to hold the replacement guide.

It's possible that if you destroy the plastic guide around it and remove it, you'll have enough sticking out that you can grab it with locking pliers and turn it out.

So, you have options, but I would wait to cross that bridge until I got to it.