Hello Stuart,
(After using 'File | Backup ...' in Hauptwerk for good measure and exiting Hauptwerk), you'd need to re-run the installer and use the 'Custom' option to move your installation. The installation paths in the installer will default to where the corresponding items are currently installed, so only change the paths for the items that you specifically want to move (e.g. the 'sample sets and components' location). Note that moving sample sets occasionally results in an incomplete move (e.g. due to file/folder permission problems on some sample set files, or device time-outs). If that happens with any sample sets then simply re-install the relevant sample sets via 'File | Install ...' in Hauptwerk afterwards.
See also the 'Changing installation locations' section in the main Hauptwerk user guide (page 30 in the current v6.0.2 version). Here's another thread on it:
viewtopic.php?f=4&t=15690