Use a plunger with a suction cup that is large enough to cover the drain (this is sometimes referred to as a flange plunger)
Fill the sink with enough water to cover the plunger top
Use a wet towel to cover the other drain opening and any other overflow outlets
Insert the plunger at an angle
Holding the plunger upright use about 15 to 20 quick strokes
Repeat this 2 or 3 times until the sink drains
Run cold water for a few minutes to flush line
If this doesn’t work you may need the line run with cable and or the high pressure water jet. Rooter Man can help call us at 504-262-8222. Ask for your free plunger!