For a single AP or multiple APs in a Zone, you can change the firewall management to the Access Points and Switches Management Management.
To change a firewall-managed AP to a Access Points and Switches-managed AP
Login to SonicWall SonicOS Management UI.
Navigate to Devices > Access Points > Settings page
Select the Access Point Objects tab.
Select the AP(s) and click on Reboot. Access Point Reboot pop-up will be displayed
Select reboot to factory default
Click on OK, to start the reboot.
Connect boot with default status AP to firewall’s non-wireless type zone or other network device, make sure AP has internet access.