Retrain soldiers

It would be great if there was a way to retrain soldiers.

Having played a bit I would like to experiment with different skills for squads, but once I’ve trained them, there is no way to un-train them to try something different. Perhaps make it a requirement that they spend X hours in a base to retrain and reuse all your XP??

It could certainly be a good option in the game menus for those who like to be able to do this.

(I personally wouldn’t, but I can understand how others might).