[Q] Best way to backup and use system from device to emulated device? topic

So while i know how to normally backup and restore phones or apps through any number of different applications or recovery software. I had an issue today where i need to backup the state of the phone as it is now, and thrn modify or test with it on an emulated device (if possible, i was thinking my laptop runninng aosp android via some form of emulation.)

Is this possible? What is the difficulty of it?

What i would be taking the device backup from is a nexus 5 with lollipop, and then from there using that as a base, figure out what is going on with the software.