Since you’re within the same major version of SonarQube, you can just do it by running the latest Enterprise Edition software against your existing database. I’d, of course, recommend backing it up first just in case. After a short schema update and data migration (which will happen on first connection from the new version) you’ll be all upgraded.
Also note that the latest release is 8.8, not 8.7, and in fact 8.9 is expected in just a few weeks!