If The SlingPlayer application is just asking for a admin password, that is something that we have not used for a few years. I would say if that is the case you will want to try to delete and install the application again. If it is still asking for the password, or on anything devices other then the phone, You will need to try to reset the Slingbox. After you can set up like it was a new unit. Here are a few articles that might help.
- Slingbox.com - Uninstalling and reinstalling SlingPlayer for Android Phones
- Slingbox.com - How to reset your Slingbox to factory settings
Hope that helps!