Quick summary:
Log into Toggle
From the sidebar click on the red icon (located in the bottom left - you might need to scroll down a bit to see it).
Then click on Account Details.
Now edit the Brand / Company name
Press Save
It might take a moment to refresh. Sometimes logging out and back in will update the name for you.
Your account name also appears on the front end of your shop which directs customers to your website.
The website link can also be edited from this page under the "Website" field.