Here is the piece at the bench ready to be worked on. Before attempting any repairs, the remaining section of the leg must be removed from the base. This allows more access to achieve an effective repair, without the rest of the base getting in the way of clamps, etc. Animal hyde glue was the adhesive of choice for many cabinetmakers prior to the 20th century, and is easily reactivated (softened) when exposed to heat and moisture. Hot water injected into the joint will do the trick. This, and some well placed clamping pressure will help to get the leg off.
The leg has been removed and the tenon cleaned of all the old glue. Notice that it is tapered, wider at the base than the top. The weight of the table pushing down on the joint locks it into place, making for a very tight joint unlikely to ever coming apart on its own.
The corresponding tapered mortice in the pedestal base.
Both halves of the leg are now free and ready to be repaired.