I don't think there is a one to one exchange thing.
Before my last in camp last year, I was issued only 2 sets (with
tags everything) by unit. If I needed more, I needed to buy more
from emart, can pay by credit. I needed 5 sets because all my in
camps are high key high key, and only high key. 2 sets just won't
cut it for 2 weeks worth of outfield.
I think it was very dumbass for my unit to issue just 2 sets for
our very very very high key battalion.
For the old sets, ST came and pick them up when they issued us
the new ones.
I recieved a mailer from my unit few days ago about the new
uniform, and if don't have them, get them made before the next in
camp at any emart or chevrons, old sets can dump there.