Degoogling does not work well, it’s best to start from scratch. But by this, you will loose the ability to use some apps from the play store. Google tries to bind programmers by offering an easy to use framework … that also sends data to google. There are ways to work around that as well. But it’s easier to use software that does not depend on Google’s framework.
A rough guideline is described here … there is no official google free image from Fairphone yet. You still need to compile the code yourself, we are not allowed to share the image, because the “bin blobs” are “protected” by a strange license.
The code complies out of the box, nobody knows the reason why they do not offer a google free image right now.