How do you get rid of really dark marks left by spots.

Lemon juice is good for acne scars. Apply them directly to the mark with a cotton bud and leave on overnight. Wash off in the morning. Repeat this every night till the scars have faded. :)

There are over-the-counter bleaching creams containing glycolic acid, kojic acid or tretinoin that will help fade dark marks and discolorations. You will find the creams at a pharmacy in the skin care aisle. If you're not sure which cream to buy, ask the pharmacist to recommend a cream.