Fruit Bat /\0/\ that would have been a better idea, but I had already started the copying. It certainly would have been a faster way.
I bought a a 1TB external hard drive (none powered) and connected the USB to the front of the Humax.
To copy onto the external drive.
Using the remote, press media, select all films and folders you want to transfer using the up/down cursor.
Press the red button to tick programs and files you want to copy onto your external hard drive.
Press the opt button and you will see copy/move select that and OK.
This brings up another selection with (HD/vidio and expansion choose expansion click OK. That's it.
To check on how the copying to External hard drive is doing during copying press media, press the blue button, and you will see the USB HD, and Humax HD, use the cursor arrows to select press OK. Press Exit when finished.
If you record during copying it may slow down the job in hand.
It took over 50 hours to copy 480GB for me so be patient, it may have been faster had the hard drive had its own power sauce.