To enter visual editing click the edit button as you see here:

Click Edit.jpg

Double-click the correct cell for the region and type its name as you see demonstrated here:

Type your region into the correct grid.jpg

Then double-click the name you typed and press Ctrl+k or click the "Link" button as you see below:

Click the link button.jpg

Then click the entry that says "Region" and then your region's name, as you see below:

Click the entry that says Region then the region name.jpg

Done. Great work!