On the website login for your wardrobe LINK. If you have your page protected by a password. You will see just under Password, Forgot Password. Click that and it will take you through a process to reset your password.
My advice though is NO, you do not give anyone out your Wardrobe Link or the password to your wardrobe.
Basically you DO NOT share your wardrobe link with anyone for any reason.
You setup a link for them that allows them access to your wardrobe give them the access that you want to give them. Read section 2.6 on this page https://purrslikeakitten.wordpress.com/cts-wardrobe/2-wardrobe-setup/
Or Butta's Youtube on Shared Links https://www.youtube.com/watch?v=VaxTr7U_DuI
As to the question of whats the worse that can happen? They could totally stuff up or delete your wardrobe via preferences. Which leads into the topic of make sure you do regular backups just to protect yourself from stuffing something up yourself.