Prepare the limeade according to package directions (usually you add 4 1/2 cans water)
Stir in the beer and tequila. Use more or less tequila to taste.
Dip the top of each margarita glass in water (or use a lime wedge to coat the top of the glass in lime juice) and then in salt to create the salt rim.
Serve over ice with lime wedges as garnish. Enjoy!