To reset your Duolingo password via desktop web, go to the Duolingo website's password settings page. Type in your current password and then the new one you would like to change it to. Choose a unique password that you are not currently using on other websites or services. Remember to select the "SAVE CHANGES" button that appears once you finish typing your new password.
On Android and iOS app:
To change your Duolingo password via the mobile app, tap the Profile tab (towards the bottom) and then tap Settings (towards the top). If you tap the Password field, you'll be taken to a new screen to confirm your current and new password.
Duolingo, Duolingo for Schools, and Tinycards accounts are one, and your username and password is shared between those accounts.
If you forgot your current password, please follow these instructions.