Open Ableton. On the left is the browser. Open the plug-ins tab and you should see ezdrummer in the list. Double click it and it should open up ezdrummer in a seperate window. Click on 'open grooves, select the relevant library and choose a beat. Click and drag your beat over to the sequencer and drop it wherever you need to. You can now also edit the MIDI track to your liking.
Bring to the boil, lower the heat and allow to simmer a while before serving...