Temporarily rooting an old 2nd generation Moto G - how can it be done?

I have an old Android phone (Moto G 2nd generation, running 5.0.2), from which I need to access files in the data\system folder. As I still do use this phone, I'd rather not permanently root it. However, I've been doing some reading, and it looks like it's possible to temporarily root it in a way that lasts until the phone is next rebooted. I've never rooted anything before, and my Googling of this only finds seemingly permanent rooting solutions. I can only assume that the terminology I'm using to search for how to do this is wrong. I'm a reasonably technical person, but I confess I am rather lost as to the correct way to proceed. Is what I'm trying to do even possible (WITHOUT wiping the phone)? **TLDR: How can I temporarily root my Moto G 2nd Gen phone running Android 5.0.2?**