When you go here: http://www.redapp.org/user/password

and enter your email or username, and click the button at the bottom of the form  the system emails you a onetime link. 

you open the mail click the link and you arrive at redapp and see a login button - Click the log in button -  just works without a password.

you are now in your account where you only have to enter a "new" password.

enter the new password twice and scroll to the bottom of the page and click save.

 

you are now logged in and your password is changed.