I just bent my yoyo factory boss axle. I purchased a new one, but I have no idea how to take it out or even put the new axle in. I tried checking on youtube, but found nothing that really helped. :’(
If the hex head hole is facing out on the old one, you can use the correct sized Allen wrench to unscrew it. If not or if you don’t have the right Allen wrench, there is also the double nut method or even old fashioned pliers since you are replacing the axle anyways. As far as putting the new one in, all you need to do is finger tighten it into one half and screw the yo-yo back together. You could also try your hand at tuning it, but that’s optional and only helpful if the yo-yo vibes.