Carpet get damp surrounded by corner of room...immediately have mildew...what is well-mannered process to remove mildew from the runner...? After I get it adjectives dry in the nouns and stop...

After I get it adjectives dry in the nouns and stop the leak (from a inner unit nouns conditioner) how do I remove the mildew stains? THANKS!

Oh ---products, techniques, anything is treatment.