Sure. Upgrading from a pre-8.6.0 release requires a fresh install. Upgrades from release 8.6.0 and newer can use an in-place upgrade, so future upgrades will be simpler.
Start by checking if you already have SLM 2.2.0 (the Serena License Manager) installed on this server. If you are running an older release of SLM that will need to get upgraded first. You can get SLM 2.2.0 from the following URL, which also contains instructions on how to upgrade: