How To Remove Background of A Photo Using GIMP

First import the photo: File -> Open.
Select "Fuzzy Select Tool": Shift + u.
On the left, select "Antialiasing", "Feather edges" and "Draw mask".
Click on the background of the photo. Hold the click and drag downward to increase the threshold and upward to decrease the threshold, so that you can select more or less.
Once you are good with the selection, let go of the selection by clicking on DEL on your keyboard.
Repeat this process a few times until it's satisfactory.