We used some L brackets to mount it to the wall, then needed to cut hole in it for the sink and put a back splash on it as well.
It also needed some more height to get the counter at the right level so we also added sofa legs to the table legs which gave us another four inches.
Then finally we painted them (we have two, one for each WC) to match the tile and wall paper.
Here is the final results, or almost final the mirror is a temporary item.