1. Extract files from com_bfsurvey_pro.zip

2. Copy entire contents (except css folder if you've customised style) of "component" folder into /components/com_bfsurvey_pro/

(overwrite existing files).

3. Copy entire contents (except css folder if you've customised style) of "admin" folder into /administrator/components/com_bfsurvey_pro/

(overwrite existing files)

4. Copy com_bfsurvey_pro.xml into /administrator/components/com_bfsurvey_pro/

(overwrite existing file)