This process must be done by a Dispatcher account in DispatchBot.  

When signed in as a Dispatcher click on More in the navigation bar and select their Dispatchers or Drivers.  The password reset process is the same.

Find the name of the Dispatcher or Driver you would like to change the password for and click their name.

In the upper right, click on the "Edit Driver" or "Edit Dispatcher" button

Scroll down to the password and password confirmation boxes and update the password.  Be sure to enter the password in each field then click "Update Driver" or "Update Dispatcher".