The phrase "altering completely" is correct and usable in written English.
It can be used when describing a significant or total change in something.
Example: "The new policy is altering completely the way we approach customer service."
Alternatives: "transforming entirely" or "changing fundamentally".
"It alters completely the way writers get treated".
A change of these fusuma will alter completely the appearance of a room, and their removal will convert two or more rooms into one.
That relief turned to joy when Commons' powerful drive just before the end of the first half changed the complexion of the game, which altered completely three minutes into the second half when Samaras levelled.
It had been an almost recreational innings, entirely free of tension or even the need to press particularly hard, the balance of the match altered completely on what seems certain to be a low-scoring pitch (if only because England are going to bat on it twice).
In contrast to bulk material, in thin nanowires, the stacking sequence changes easily, and under particular growth conditions can be altered completely to the wurtzite (WZ) crystal structure [8].
The landscape of the game had altered completely and, with 20 minutes left, McLeish introduced Agbonlahor, who had been struggling with a shoulder injury in the build-up to the game, for Heskey.
I've found that my words have been altered completely in some news pieces and that's also frustrating.
Yet when these inherently unpredictable events occur, they alter completely the course of our future in ways we can never anticipate.
I'm exaggerating, of course, but that will help me greatly and alter completely the political situation internationally and within Arab ranks.
A few anchovies are melted into the sauce (their taste alters completely when they are cooked), making it richer and more complex.
