Erice, my mast base (home made) is not captive. It is basically a cilinder with a half spheric hole that fits the ball. There is a critical angle above which the base will remain on the ball. That ladder could be a good support support to ensure you don´t go below that angle, either for raising or for lowering. I always use a safety line in case it pops out, but I proceed that way. Even with a lower support: the mast cradle of my trailer, which is probably too low. If the beach has a slope (as usually), the bows should be pointing towards the water. That way the mast will rest on the shrouds and you will be able to attach or detach the forestay yourself.
If there is nothing to use as a support, I ask somebody to help me get started, holding the mast from the tip and walking towards me, to get a better starting angle. To lower it, having someone to receive it is more dangerous, sometimes I just let it touch the sand, it will pop out of the ball and the safety line will work, but it goes down smoothly enough (you won´t be able to hold it though, it will fall down). Last time I did it towards the water, I asked my wife to detach the forestay. It´s a good opportunity to check if the mast is still watertight. Make sure that there are no kids around and also do it after disassembling the steering. And stay on the tramp, it´s not a good idea to walk on the sterns, the boat will want to sit on the sterns and raise the bows. (Well, mine is a 5.0, not a 5.2, there might be differences regarding the last issue)