Change the linked lol acc with twitch prime?

Since this season there's this twitch prime loot in Lol if you link. Only I have connected this with an acc I do not use anymore, but somehow you can't change the acc, since I'm now only getting prime loot on my lost acc, you can change that somehow.

Believe you have to relink this in the twitch settings. Since the process is very well described.

I do not know if you will get the already received loot, but honestly I can't imagine.