Hi Jo,
Found this KB article if you want to disable from the GUI.
https://support.ruckuswireless.com/articles/000002652If you are not able to get the GUI follow the below steps:
1. SSH into the AP.
2. enter the command "set https enable".
3. Now you should be able to get the GUI access.
If you are able to get into the GUi but unable to see the configuration option.
Then it means the AP is probably managed by the controller.
Follow the above steps to gather the controller information. Once you got it, you can disable the WLAN from the controller GUI for the AP under "Access Points" section.