This is fine if you're home alone, but around people, do NOT remove the cork cage beforehand. Untwist the wire but DON'T remove the cage. Don't remove all of the foil, only the upper portion. Leave the rest of the foil, scrape a path along the MAIN seam of the bottle up to the neck. Strike along that path with the BLUNT side of the blade, NOT the sharp end. The champagne that pours out will take out any broken glass, and contrary to what some think, the champagne is NOT ruined.