Hi @chloe-annelise,
Thank you for your question and welcome to the Bunnings workshop community, it is fantastic to have you with us.
That's a tough one because the brackets on the back of the door appear to be tack-welded to the back of the door so replacing the actual door itself is likely not possible.
My suggestion is to have the mirror removed and replace it with a new one. Due to the risks involved with removing the old mirror, I'd suggest this is something that should be done by a glazier or handyman who has some experience with glass.
Once removed and cleaned up, you could stick a new mirror in place with Selleys Liquid Nails Mirror Metal And Glass Adhesive.
Let me know what you think.
Jacob
