Note- There are two options, migrate to another network, or migrate to a specific ip.
Migrate to another network will take the first available IP in the new subnet.
To Migrate to a new network
Select IPAM> Addresses
Select the current address
...
enter the new network IP
click OK
To Migrate to a Specific IP
Select IPAM> Addresses
Select the current address
click the Tools drop-down list
select Migrate to a specific IP
a wizard window appears
Fill in the fields
Source Space
IP address to migrate * Required
Target Space
New IP Address *Required
Click Okay