This is my first time with QGIS and maybe it is an easy question but I can't figure out how to cut part of a layer to add it to another one.
In the image you can find (red circles) parts of a layer totally embedded in other layers. I would like to "cut" that parts and join/add to the surrounding layer.
I have tried to freehand selection tool but after defining the selected area the whole layer is selected. I just want to select the embedded piece, then create a new layer and add to the surrounding one.
Shapefiles have only one attribute, so I can't (do not want) to select by attribute but for region.
Shapefiles available in this file (Dropbox link)
I'm using QGIS 2.18.3 under Ubuntu 16.04.
As a novice any idea or advice is welcome