Re: how do i restore an iPhone 6 from iTunes ?
So you have a usable backup of your iphone on iTunes?
If so, connect your iPhone to your compter by the cord (use the official one, not an after-market, if you can as whilst the after-market cords don't always cause a problem, it's better to take that possibility out of the equation straight away).
Then click the Restore Backup button, after making sure you have a backup to restore from.
It should NOT take 48 hours, nor should it even take 10% of that time. It should be done relatively quickly, depending on how much stuff is to be put back on the device.
If none of that works, try restoring from a different computer and manually copying over the backup from its location on the first computer, to an identical location on the second computer. It helps to make a backup on the second computer so you now the file path fr the original backup to go into. I know this seems convoluted by my home PC back in the UK just doesn't like restoring from backups, or updating software on my iPhone or iPad through iTunes. One f my other PCs works perfectly, so now I back up and restore to that one instead.