Forum Monoray.net

In my webmaster tool, under HTML Improvements . I am getting below 12 pages with duplicate meta description.
1.Where i can change these description?

Site with advertisements of properties for sale and for rent. Sell and Buy Apartment,House,Land and

Below are the pages having this duplicate meta description.
/contact-us
/faq
/guestad/add
/page/2
/property/212
/property/259
/service-47
/service-51
/service-52
/service-57
/service-62
/site/login

You can buy SEO-module to change title and META-keywords and descriptions.