Once you have created your shop (admin or player), there are various actions you can perform to either customize your shop further, or delete it again. This page describes how editing of shops works in general, and what the available actions common to all shop types are.
Opening the "Editor Window"
By right-clicking on the shopkeeper while sneaking, you can open the shop's "Editor Window". This will look like a regular chest inventory, but it has a couple of special icons. Those represent buttons you can click to perform certain actions on the shopkeeper.
Example of the (empty) admin shop editor window:
Renaming the shop
To set the shop's name, click the name tag and then type the new name into the chat.
The new name gets verified using a regular expression specified in the config. This regular expression specifies the allowed characters, as well as the allowed minimum and maximum length of the name.
Changing the object variant
Some shop object types provide multiple variants you can select from inside the editor window. For example, for a villager shopkeeper you can cycle through the various villager professions and biome types by clicking the corresponding items.
Deleting the shop
If you want to delete the shopkeeper, you can click on the bone in the bottom-right corner. Be careful, there is no undo!