Adding new keys to a keyring is a fiddly job - you have to prise apart the parts of the ring and hold it open long enough to get the new key on.
My current method is to pull it apart with my nails wide enough to push the key in flat, then I lever the key upwards to get it in the rest of the way.
This kind of hurts my nails. Is there a better way of doing it? I saw some suggestions online to use a staple remover, but that's not something I've ever owned or had a need for, so I don't want to buy one specially.