When you click on your profile, there's an "edit apparel" tab bottom right. Try clicking it, maybe it'll work even without a neon sign pointing on it ;-) Then you need to click separately on hats, golves, etc. If you can read, you'll figure it out.
But if you don't want to upgrade anything, you don't have to. I've lived with that red dot on my profile pic for a while now, still able to play... ;-)