1. Obtain Nep Nep

If you want to nep a Nep Nep, first you need to obtain a Nep Nep. This Nep Nep on the left looks good. Perfectly neppable. This Nep Nep on the right is not neppable. In fact, it isn't even a real Nep Nep. Notice it only has one plus accessory in her hair. This is Nepgear. Nepgear isn't Neptune. Neptune is Nep Nep. Get Neptune. Not Nepgear.