When Wi-Fi Direct (simple AP) connection is enabled, you can change the settings from 
> Wi-Fi Direct > Start Setup > Change, and then the following menu items are displayed.
Change the Wi-Fi Direct (simple AP) network name (SSID) used for connecting to the printer to your arbitrary name. You can set the network name (SSID) in ASCII characters that is displayed on the software keyboard on the control panel. You can enter up to 22 characters.
When changing the network name (SSID), all connected devices are disconnected. Use the new network name (SSID) if you want to re-connect the device.
Change the Wi-Fi Direct (simple AP) password for connecting to the printer to your arbitrary value. You can set the password in ASCII characters that is displayed on the software keyboard on the control panel. You can enter 8 to 22 characters.
When changing the password, all connected devices are disconnected. Use the new password if you want to re-connect the device.
Disable Wi-Fi Direct (simple AP) settings of the printer. When disabling it, all devices connected to the printer in Wi-Fi Direct (Simple AP) connection are disconnected.
Restore all Wi-Fi Direct (simple AP) settings to their defaults.
The Wi-Fi Direct (simple AP) connection information of the smart device saved to the printer is deleted.
You can also set up from the Network tab > Wi-Fi Direct on Web Config for the following settings.
Enabling or disabling Wi-Fi Direct (simple AP)
Changing network name (SSID)
Changing password
Restoring the Wi-Fi Direct (simple AP) settings