I would take the following approach:
1. Disable auto AP join on your ZD
2. Configure DHCP on your ZD to assign 1 x IP address
3. Remove AP you no longer want on the ZD from ZD AP table
4. Factory reset AP
5. Check your ZD DCHP server to obtain the AP's IP address
Note: You can also do the following steps if you would like other AP's to auto join your ZD in the future, but stop that AP from joining6. Flash the AP with base 100 image
7. Disable discovery agent:
set discovery-agent disabled
8. Enable Auto AP join on ZD
Good Luck