This is not the world's busiest message board -- so I would not equate silence with disinterest.
The EVO batteries are designed to internally adjust their charge for storage... After a few days at a higher charge (>50%), batteries will automatically discharge a bit every day until reaching ~50%. After this, the charge will naturally fade through ordinary leakage, but will keep most of the remaining charge for many months. For example, my own batteries this last spring were at ~40% after six months in storage.
If I am not planning to fly anytime soon, I charge my batteries to somewhere above 50% (or leave them alone if this is already the case). Once charged to at least 50%, I can store them pretty much indefinitely. (Personally, I would charge them back up to ~50% at least once a year).
I'm sorry, your question was about HOW to put the battery into storage mode. With the drone on, look in your app and see if there isn't an option to select how many days to wait till self-discipline starts. You can't just "switch it" to self-discharge mode.