Change "Login within Wordpress" in Appointments+ plugin

Hi,
I want to change the mssage shown at this page http://tuuway.com.previewdns.com/joes-schedule/ to say "Login with your Tuuway account" and not "Login with Wordpress". I have drilled into the php and js but cannot locate the origin for line 73 on this page source where this is referenced.
Thanks,
Ivan