I just purchased an Ewire 2701, second-hand router for WIFI and don't have any manuals for it.

The default password to allow devices to access the wifi is on the back of the router along with the router's system password (used to change settings). If this information is not there of faded the you will have to access the router for that information.
To access the 2701 plug into it directly with an ethernet cable. Open Internet explorer, (at&t products can be picky about the web browser) got to http://gateway.2wire.net. This will take you to your router's home page. Click on home network then wireless settings and the information will be there. If you want to start over with a fresh router hold the reset button on the back of the router for 40 sec. That will reset the router to factory settings. http://www.2wire.com/pages/pdfs/2701HG_user_gui... is the web page manual for your router. If your router is different go to www.2wire.com and search for the model number on your router. Let me know if you need more help.