1. Click on your avatar
On the top right hand side of the page is located your avatar. Simply click on it.
2. Generate Password
Scroll down to Account Management and click Generate Password. WordPress actually generates a secure password for you and shows it to you, however you can still input your own if you so desire.
3. Hide Button
You can click the Hide button to hide hide your password on the screen.
4. Update Profile
Once you are done setting up your new password, simply scroll to the bottom of the page and click the Update profile button.