Rinse the chicken breasts and pat dry.

In a large bowl, combine the sour cream, lemon juice, salt, Worcestershire sauce, garlic salt, paprika, and pepper.

Roll the chicken breasts in the sour cream mixture until well-coated.

Place them in the bowl and top with any remaining sour cream mixture.

Cover the bowl and refrigerate overnight.

Preheat the oven to 350°F (175°C).

Remove the chicken breasts from the sour cream mixture, taking up as much of the mixture as possible.

Roll the chicken breasts in the breadcrumbs to coat well.

Place the coated chicken breasts in a baking dish.

Mix the melted margarine and butter together.

Pour half of the melted butter and margarine mixture over the chicken breasts.

Bake in the preheated oven for 45 minutes.

Pour the remaining butter and margarine mixture over the chicken breasts and bake for an additional 5 minutes.