Unable to upgrade to BlackBerry 10 OS version 10.3.1 due to insufficient space
by Volker Weber
The BlackBerry 10 OS requires 2.5 times the downloaded package size, for example, an update package of 1GB will require a total of 2.5GB's free space to download and install successfully.
I would install via PC or Mac and BlackBerry Link. That requires a lot less space.