Instructions can be found by Googling. A quick temporary to fix it from doing things you don't want is to find it in Settings, Apps and one of the sub-menus will give the option to Force Stop (and the delete option) . Note if you click on the icon after that it will stàrt again and you will have to Force Stop again.
Factory reset will lose all your data and settings. Consider backing up, Settings, search for Backup. If you have a Google account back up there. (If you have enough data in your plan set automatic backup whilst you are there).
