Install the JRebel MyEclipse plugin by going to Help » Install New Software...
and use the URL :
http://www.zeroturnaround.com/update-site/
For offline installation use the downloadable zip archive instead:
http://www.zeroturnaround.com/update-site/update-site.zip
If you chose not to use the embedded JRebel, you need to specify the path to jrebel.jar manually. Go to Window » Preferences » JRebel, browse to the
installation directory and select the jrebel.jar
There are also some tweaks to be done in the debugger settings. Go to Window » Preferences and from there to Java » Debug » Step Filtering.
Check Use Step Filters, Filter synthetic methods, and Step through filters. Now check all the default filters and use the Add Filter button to add com.zeroturnaround.* and org.zeroturnaround.*.
For best experience, go to Project » Build Automatically and make sure it is checked.