Hi Patrícia,
well you can of course export the method and impact categories from the EF3.1 database (as JSON-LD, e.g.) but they are, on purpose by the EC, not meant to be used with other databases and flow reference systems thus this does not really help. We just reuploaded the EF3.1 method adapted to the openLCA flow reference system (check in Nexus), if you are "only" after the LCIA method.
All the best,
Andreas