A user's Apple device is restarting randomly. He hasn't recently installed any new software. What are the TWO things you should do to fix the problem?

According to Apple.com, you should contact Apple Support if the problem persists despite everything being up-to-date and your battery being in good condition. Most batteries are not user-replaceable. Before contacting Apple Support, make sure you back up your data since if you restore the phone to its factory default settings, everything on the phone will be lost. Resetting the phone to factory default isn't Apple's recommendation.