UK?CAN/AUS/NZ/RSA/USA Proofreader and Editor is needed.$1/500-600 words

Hi, I am looking a native speaker. I have 10-15 articles for proofreading and editing! These are written. You have check for errors. You must replace those words or lines with new ones. You have to set the keyword density! You have to edit and proofread [login to view URL], you have to make some modifications in the articles to make them [login to view URL] have to add some information or you have to write 75-100 words in some articles to balance the needs of the articles. Each article will be of 500-600 words(Mostly, 500 words). Please, set your bid rate according to the mentioned price for 10-15 articles i.e. $10-15 for the total project. Only Native speakers. Thanks