Hi,
You can use the Firepower Migration Tool (FMT), this supports multi-context migration (one context at a time). You can migrate the interfaces, routes, ACL, network/port objects, NAT etc. When you run the FMT tool, it will import the entire ACL if required, or you do have the option to select which rules to not migrate. It will create a new Access Control Policy on the FMC to be applied to the FTD.
HTH