To use Sound Packs in Ableton Live, simply add a new MIDI track, navigate to the plugins section and find the Reason Rack Plugin.
Drag the Reason Rack Plugin into the MIDI track. This will trigger Reason to open. From there, open the browser by clicking the grey circle in the top left, and then you will a shortcut for Packs.
Find the Pack, open it and drag one of the patches into the rack.