I have an axe with a damaged handle that needs replacing, but I don't know how to do it. What tools and techniques should I use to get the job done?
You'll have a couple choices when replacing the handle, you can either get a good Hickory replacement handle like this,
or a Fiberglass handle like this.
Comparing handle types is beyond the scope of this answer.
Either way the repair starts the same way, by removing the old axe head. This will likely be the most difficult part of the job, as the handle was installed to not come out. You may be able to drill out enough of the material, so the handle will easily slide out. You could also try removing the metal and wood wedges (reverse of install) to remove the head, but sometimes the wooden wedge is glued in so you may not be able to remove it. If the old handle was fiberglass, it may be easier to purchase a new axe. Removing the old epoxy can be difficult, and time consuming.
Once you have the old handle removed, the installation of the new one is slightly different depending on the handle you've chosen.
Installing a Hickory (wood) handle:
It's best to buy a replacement handle that includes everything you'll need to install it, which will likely come with a notch already cut in the top of the handle (so you won't have to cut this yourself). If you can only find a handle with a wooden wedge and no metal wedges, the metal wedges are available separately.
Installing a Fiberglass handle:
When purchasing a fiberglass handle, try to find one that includes the epoxy. If you can only find handles, the epoxy kits are available separately.
When installing a fiberglass handle, you'll have to make sure the hole in the axe head is clean. You can use sand paper, or a small round file to clean the hole before installation.
Standard guidance seems to be:
I've only done this once but it was good fun. Get the wedges in solidly to avoid the axe head flying off, though:-)