Question : Problem: IOS to LWAPP downgrade

whats the procedure to change from cisco ios to LWAPP on a aironet 1200 series ?

Answer : Problem: IOS to LWAPP downgrade

Ok..These access points  can only communicate with 2006 series or 4400 series controllers; they do not support Layer 2 LWAPP. They must get an IP address and discover the controller using DHCP, DNS, or IP subnet broadcast.

So no, you can't downgrade them.