Here are instructions from mobilegeeks.com for both soft and hard resets. I think you should be ok with just a soft reset, which should bring the device to it's initial software OS and settings.
"How to soft reset a Moto G
◾Turn your phone on and unlock the screen.
◾Access the Settings app.
◾Scroll down and tap on “Backup & reset”.
◾Tap on “Factory date reset”.
◾Select “Reset phone”.
◾Let the phone do its thing. It will restart once it’s done.
How to hard reset a Moto G
◾Turn off the phone.
◾While off, press and hold the Volume Down button for 2-3 seconds, then press the Power button and release.
◾The device will display different booting options.
◾Use the Volume Down button to scroll to “Recovery” and press Volume Up button to select.
◾The phone should display a Motorola logo, as well as the Android in Distress image.
◾Press and hold Volume Up for 10-15 seconds.
◾While still holding the Volume Up button, press and release the Power button.
◾From here, you can use the Volume buttons to navigate and the Power button to select.
◾Select “Wipe data / factory reset”.
◾Select “YES – delete all user data”.
◾Once the formatting is complete, press the Power button to confirm a reboot."