I don't have any photos of the mast raising setup, and won't be near the boat until at least this weekend. I'd search online for posts and videos like "mast raising gin pole" or "mast raising system" and you will find examples. Some Hunter boats (I think mainly the water ballasted boats?) came with that system, and have fittings to attach the pole to the mast. The 23 did not, so the person I bought the boat from did his own (by drilling holes in the side of the mast, unfortunately).
The gin pole is a stiff pole, maybe aluminum tubing or stainless, even wood or stout PVC I suppose, that attaches to the mast base near the bottom, as close to the swivel on the mast foot as possible, facing forward. It does not have to be fixed so it cannot tilt up and down, just so the attachment point does not slide up and down the mast tube. On mine, the PO (previous owner) used pretty thick walled aluminum tubing, and made a u shaped bracket from thick aluminum plate that wraps around the mast from the rear, and has bolts through the mast sideways to hold it. I would think you can fashion something like that from wood that clamps to the mast (but not so tight to crush it).
The pole extends horizontally forward (when the mast is up) to just short of the forestay attachment, maybe about 3 or 4 inches short. It need some sort of attachments (in my case eye bolts) so two lines can be attached, one each on the upper and lower side, right near the end by the bow. The jib halyard goes down to the eye that is on top, and is then cleated to its mast cleat so it makes a right triangle between the pole and the mast, where the halyard is the hypotenuse. The pole may be slightly above horizontal (a bit less than 90 deg to the mast). Picture it when the mast is down - the pole sticks up. The block and tackle you use to pull it up pulls on the bottom of the pole, and the triangle shape provides a much better pull angle than if you just attach the halyard to a block and tackle.
It is also helpful to have "baby stays" that support the mast sideways as you lift or lower it, unless you always have a helper or two to support it - it will want to lean over to the side, which can break the mast foot fitting (don't ask me how I know).
Now, I am assuming that year 25.5 did not come with any sort of mast raising tools. My '91 23 did not, so I assume this was a newer improvement for the trailerable boats.