Note that step 5 specifies “without code” but you can actually enter your old sensor’s code number at that point. So I always take a picture with my phone whenever I start a new sensor so I have the code handy when I roll it over.
Basically the idea is to insert a new sensor ~24hrs before the current one runs out. This gives it a longer acclimation period than the statutory 2hr warm up. By most accounts this helps keep the new sensor from being so erratic at the start of a session.
