1. If you do not have a store account then please create a new one here (if you do have a store account then please skip to step 3): https://login.bistudio.com/signup
2. Activate your account via the link in the activation email.
3. Log in here: https://store.bistudio.com/
4. Click "Claim for free" on the Minidayz entry in the store.
5. Click on the "Play" and you will be redirected on the Minidayz page.
You can access and play the game directly here: https://dayz.com/minidayz