I found that here in the 1200 documentation could also work I never use that before:
Resetting to the Default Configuration
If you forget the password that allows you to configure the access point, you might need to completely reset the configuration. Follow the steps below to delete the current configuration and return all access point settings to the factory defaults.
Note 
The following steps reset all configuration settings to factory defaults, including passwords, WEP keys, the IP address, and the SSID. If you do not need to reset the entire configuration, use the Configuration Reset buttons on the System Configuration Setup page in the web-browser interface. Consult "Downloading, Uploading, and Resetting the Configuration" section for more information on the reset buttons in the web-browser interface.
Step 1 Connect a nine-pin, female DB-9 to RJ-45 serial cable to the RJ-45 serial port on the access point and to the COM port on a computer.
Step 2 Open a terminal-emulation program on your computer.
Note These instructions describe HyperTeminal; other programs are similar.
Step 3 In the Connection Description window, enter a name and select an icon for the connection and click OK.
Step 4 In the Connect To window, select the port to which the cable is connected and click OK.
Step 5 In the Port Settings window, enter the following settings:
•9600 baud,
•8 data bits,
•No parity,
•1 stop bit, and
•No flow control
Step 6 Click OK, and press Enter.
Step 7 When the Summary Status screen appears, reboot the access point by unplugging the power connector and then plugging it back in.
Step 8 When the access point reboots and the Summary Status screen reappears, type :resetall, and press Enter.
Step 9 Type yes, and press Enter to confirm the command.
Note The resetall command is valid for only 2 minutes immediately after the access point reboots. If you do not enter and confirm the resetall command during that 2 minutes, reboot the access point again.
Step 10 After the access point reboots and the Express Setup screen appears, reconfigure the access point by using the terminal emulator or an Internet browser.
