Metakgp:SysAdmin/Reset server password for a user

Requirements:
YOU must have ROOT access on the server
The username of the user who has forgotten the password is username
Process:
Change the password of the affected user to a known value. sudo passwd username. Now, enter the new password. Call the password NEW_PASS
Run the command sudo chage -d 0 username. This will make sure the user is forced to change the password when they login.
Share the value of NEW_PASS with username. They should be able to login. On login, they will be asked for the current password, which they must fill out as NEW_PASS and the new password, which they can fill out as any valid Unix password.
Concise procedure:
sudo passwd username
sudo chage -d 0 username

Source: https://metakgp.slack.com/files/T0AHQ612B/FU4GHLMNJ