I have Lubuntu 14.04 (and Ubuntu 14.04) on a pair of USB disks created by writing the img files to USB using dd on Mac OS X.

Unfortunately these systems both have some known bugs (that have since been corrected) and lack certain important drivers for my system (which I have located online).

How can I make the USB disks writable and how do I update the distribution upon them as one may do for a locally-installed system?

And if I later proceed to install from these USB sticks onto a hard-drive, will they ‘carry’ the package and driver updates with them or will I have to start from scratch again? (I seem to remember from my ancient Windows XP days that such procedures were referred to as ’slipstreaming’ or somesuch on that side of the fence.)

(No, I did not create a persistence partition when I created the sticks, because from Mac clearly that isn’t an option. And anyway, as I imperfectly understand it, the persistence partition is for user files and not for the modification of the system.)