Renovation clean up

Renovation is done. Now it is clean up time. -There is some purple stain on my tub that the plumbers left. What is the best way to clean that off? -There is paint and plaster on my white baseboard coat what is the best way to clean that off http://slantfin.com/products/baseboard-residential.html? The white base board also has scratches what is the best way to fix that?