Thanks for that writeup DnvrFox. But note that it's a stop gap intended to allow someone with no skills/never took any CPR training at all to at least do something that will help with minimal information over the phone. It's not a replacement for the better method given by a person with the proper training.
While it's likely better than nothing at all a better option is to take the proper course. In the course they'll teach you to use the proper technique for mouth to mouth and how to properly do the heart compressions without hurting the victim more.
Which, by the way, also suggests that even a minimal first aid kit should have a disposable plastic mouth barrier in it. They aren't any bigger than a larger bandaid when in the package and fold out to cover the victim's mouth in case you're worried about disease contamination. They cover these in the proper CPR course.