Like every blockchain, once a user create account on breeze blockchain (signup on TipMeACoffee) he gets his private key (password). User needs to make sure that he securely saves this private key as all his funds and data is controlled by this private key and if he loses it, breeze will not be able to recover it.
Users can change their private key at any time in their wallet on TipMeACoffee under keys tab but again it is important to mention that this new key must be saved securely and should not be shared with anyone for the sake of account security.