If you already have installed the plugin from the YourKit Java Profiler version you use (i.e. having the same update site URL - see below), just make sure it is up to date: go to Help | Check for Updates in Eclipse's main menu.
Go to Help | Install New Software... in Eclipse's main menu:
Press "Add..." button:
Copy appropriate URL:
|YourKit Java Profiler 2017.02||
|YourKit Java Profiler 2016.02||
|YourKit Java Profiler 2015||
|YourKit Java Profiler 2014||
... and paste it to the "Location" field:
Important: Eclipse update manager needs internet access. If your computer sits behind a proxy server, you will need to configure Eclipse accordingly: go to Window -> Preferences, then General -> Network Connections and enter the host name or IP and port of your proxy server.
If there is no internet access, use the bundled update site archive:
<Profiler Installation Directory>/lib/eclipse-plugin/yjp<version>_for_eclipse.zip
Select YourKit Java Profiler plugin and press "Next":
After restarting Eclipse, you should see Profile action in the toolbar: