In order to change password of the user:
Go to the System workplace, and open the Users tab
Click the pencil icon next to the user, whose password needs to be changed.
Edit user page will emerge. Click the pencil icon next to the password field
The pencil will change into an eye. Enter the new password there
If you want to see the password, click the eye icon.
Scroll down the edit user page and click OK to save the changes.