As I recall from memory (I was surprised that the process was roughly 15 minutes in total), they asked for the AirPods. Then they did a visual inspection and wiping. Then they paired the unit with their service iOS device. They replaced the ear tips with their service one, then the staff placed it in their ears. I think the service device has a "sound quality testing mode" since the staff noticed that the left one has static issues as well even if I've only noticed it on the right one. The staff also did some tapping of the Airpods (which I do as well since that's when the static and pops occur as well). Then they asked me to fill out a form for the service. They mentioned that there will be succeeding checks after that ( I think, it is just to see whether it has liquid/other damages aside from the static issues).