Lactic acid is cleared from the muscles within minutes of exercise. The pain that you're feeling is what's known as delayed onset muscle soreness (DOMS for short), and is caused by microscopic muscle damage and the inflammation that follows. The only thing that can get rid of it is time. You can carry on as normal- go for a ride if you can tolerate it, because increasing bloodflow to the area can only be a good thing (though there's no research that shows 100% proof that it's going to help), and, even though it will be somewhat painful, it's not going to cause any more damage.