When I first turned on my Surface Pro, before I could do anything else, it asked to do an update, which took around 24 hours to complete (I don’t know if this was due to bandwidth issues, the budget processor inside, or what).
Upon completion I was able to have a play and fully explore the device, with one of the first thing I did being to take a look at how much storage was left over - at which point I was shocked to discover than half of the 128GBs on the device was taken up by the preinstalled software.
I later discovered, as suggested by @Mr_Tom, that at least half of this was the backed up version of the pre-updated windows 10, which I was able to remove via a combo of the options within Windows, and CCleaner.
Mind you, that was still 32GBs just for Windows.
It was this, moreso than anything else, which made me suggest he take it back. I’m sure there probably is a way of getting it to update via the removal of various backups, etc… but it all sounds like far too much effort to me.
A nice Kindle Fire HD 10" should be more than suitable for his needs.