you can however kill the red by giving it a coat of grey
you use a roller, but brush the edges just before you roll them. You will probably get some paint on the walls, rub away any drips with a damp rag, and repaint the walls once the ceiling is dry. To get a neat line betweem wall and ceiling, use a small brush, well-filed with paint, after both ceiling and wall are dry. Use a damp sponge to clean off any excess before it dries.