Lost Mine of Phandelver Hidden Tokens

I'm working through Wave Echo Cave as the GM, and I can't seem to get access to the hidden tokens, like Mormesk. I found a forum that advised: "As GM click over to the GM Layer," and then shift Mormesk to the token level, but when I try to do that, I accidentally turn the map into a token, which is not what I want. I'm sure I'm doing something wrong, but I don't know what it is.

In a related issue, it seems like I should be able to drag a character from the bestiary and place it on the map, but that doesn't work, either. I'm sure it's all operator error, but I can't find answers that provide me the relief I seek.

Okay, I just figured out that shifting to GM Info Overlay makes it possible to manipulate hidden tokens and put them on the token level. I'm quite slow, apparently.

Anything on the GM layer is invisible to players.  Tokens on the GM layer will also be hidden from players on the initiative tracker until the token gets moved to the object/token layer, so you can roll initiative before a session or whispered to the DM and players won't know about those tokens at all.  Basically, you generally want to keep things on the GM layer until they are actually needed in play.