I've never done this and slightly unsure how so I thought I'd ask some that has already gave his leading position in a alliance to a person of choice. How can I give my leading position to another member of my choice?

If I remember correctly, which I probably don't, there should be a 'transfer alliance' button near the bottom of the alliance page. Press that.

I lead RWH once and tryed that transfer button, a failure. perhaps it has something to do with the Right hand right, in the configuring rights section of the alliance? then the transfer button, because as of now I've not noticed in all my time here any benefits of the Right hand rank, perhaps that is the way to promote another leader for a alliance.

this might work.promote the person of your choice to leader then demote yourself.

did that also it just deletes all the ranks.

I transfered an alliance pretty easily before. Just have one person (only one) with the right hand right and hit transfer, and it worked for me.