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

click the Edit drop-down list

select migrate to another network

a wizard window appears

select the target Space from the drop-down list

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