1. Download the theme.
2. Extact the compress file.
3. Goto extact theme folder-> app-> design-> frontend-> default and copy theme name folder.
4. Goto magento folder-> app-> design-> frontend-> default and past here.
5. Goto extact theme folder-> skin-> frontend-> default and copy theme name folder.
6. Goto magento folder-> skin-> frontend-> default and past here.
7. Goto admin panel and login.
8. Goto System-> Configuration-> Design-> teme fill all field with your theme name.
9. Goto System-> Design and Add Design Change and select Custom Design “your theme” if design is already created then update it to select new theme name.
10. Check your homepage.