Reset password wither if you want to change the exiting password or if forgot the password and want to reset it ,  is a self-service that can be done by yourself by following the below steps:

You can simply reset your password at the login page by clicking on "I forgot my password"

Then it will ask for your user name /Email & write down the security code , then will send you the reset link via Email :

IF you want to change your password , but already remember your logins , go to :  Settings Tab > Password Settings and then change password .