Data migration between different versions of Neo4j

We recently update our community Neo4j server from 4.0.2 to 4.2.4.
What is the least painful way of migrating our graphs from 4.0.2 to 4.2.4?

Thank you

If this is an in place upgrade then simply update conf/neo4j.conf and set dbms.allow_upgrade=true ( Configuration settings - Operations Manual )
and restart Neo4j