Cut the stem of the roses diagonally, at about a 45-degree angle.
Fill a vase with warm water mixed with a floral preservative.
Place the roses in the water and then move the buds to a sunny location until the buds have started to open.
Remove the roses from the vase and then dip the heads in water.
Place the rose heads in a plastic bag and replace the buds in the sunny location until they have bloomed. Blooming time depends upon the individual stem, but expect them to bloom and open in about 24 hours.