Forza 6 update gets to 31%, then goes back to 1%

Hi Guys, I’m new to XBox so go easy on me.
I’m trying to download and install the update for Forza 6 but it gets to 31% and then goes back to the start. I’ve tried many times and it just does the same loop.
I’ve tried turning off and unplugging the XBox too, but had no luck.
Is there any way of fixing this issue or updating the game via USB?
NOTE: My copy of Forza 6 was a download version and I’m not very keen on uninstalling it and downloading it again as it munched 95% of my monthly internet the first time.