How to unlock the sections on your layout tab in Blogger in order to be able to add more gadgets to them

Nowadays there are a lot of sections on your layout editor for header elements such as sliders, additional menus, featured post widgets and much more - and most of them are locked! You do not see that lovely blue "add gadget" thingy on them. 

Here's how you unlock them, and it is really easy. Find these code pieces (there will probably be more than one) in the HTML editor:

showaddelement='no' 

and change the 'no' to 'yes'. Instead of 'no' you may also have 'false', in which case you change 'false' to 'true'.  

That easy!