Upfrading from Ubuntu 14.03 to Ubuntu 16.0

[Peter]

The password problem was simple to solve, although on all the Linux 
boxes the user name is Peter, the termina requires it to be entered as 
peter. The passwod worked and logged nin to a terminal session fo Linux 
16.04. I thus have a partial installation. I can see all of my home data 
files etc and can restore them from backups, but I need to know how to 
either return to 14.04 or complete the installation of 16.04.

Is it possible to restore the 14.04 without overwriting the datafile 
directories?

Regards

Peter Goggin