I have a twenty year old kitchen ceiling which is a medium orange peel texture, painted in semi-gloss. I need, because of making it larger by removing a wall, to make the texture a knock down. IF I clean the ceiling with TSP, rinse and prime, will this be adequate for the knock down texture to be applied upon? OR should I rough the orange peel up after the cleaning and before the priming? Or should I do only some but not all of the aforementioned? Thanks very much for your answer. Eric

Just priming it should be fine, the TSP may not even be necessary.