If you’re using the website: to change your password, click on the "gear" icon in the upper right hand side of the screen that goes to "My Account". Click on the "Settings" tab and the 2nd from bottom option is “Change Your Password”.
If you’re using the new Grokio communities app: navigate to the bottom right tab “Me” and then scroll down where there is a “Change Password” button under your account options.
If you're using the old app: click on the 3 dots in the lower right hand corner for "More" menu. Tap on "My Profile" and click on "Change Password".
The Grokio team