Hi Ivan,
The AP CLI script to change the APs to fetch IP from DHCP server is below.
fw_version=3.1.1.0.349 ( change this with your AP firmware version )
model=all
set ipaddr wan dynamic
reboot.
Please be cautious when using this, when doing this you have to make sure that AP show connected on the controller else it would fail.
Let me know how it goes.
Thank you,
-Abilash PR.