Here's how you can switch from an icon grid style collection to a reading list:
First, click on the title of the collection you wish to modify.
Next, click the Display option to toggle the collection style.
The collection will now appear as a reading list, and you'll be able to see a title next to the icon.
If you need to rename a bookmark, click Edit Mode or press Shift+E on your keyboard.
Next, click on the bookmark you wish to edit and select Edit from the dropdown menu.
Give your bookmark a new name, and click Save.
Here's a short video tutorial: