First of all, you will need to get in touch with the legal registrars - Computershare. If you have an Investor Centre account, you can log in there now!
A few bits of info you will need handy:
Your full name
Your shareholder number
Your previous postal address
Your new postal address
Your contact email address
You will also need to update it on your brewdog.com account - to sign in go here: https://www.brewdog.com/members/login
Once you're logged in click on the 'Edit Details' tab.
You can update your billing address and also add any delivery addresses you'd like on file for deliveries/ orders.
Please note, that if you change this manually on your account, this will not automatically update Computershare.