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)

5. Run the following mySQL commands in phpMyAdmin

ALTER table `jos_bfsurvey_pro` ADD `validation_type` varchar(50) NOT NULL;
ALTER table `jos_bfsurvey_pro` ADD `field_type` varchar(50) NOT NULL;

For all answer tables in the form jos_bfsurveypro_xx (where xx is your category id number)
ALTER table `jos_bfsurveypro_xx` ADD `uid` int(11) NOT NULL default 0;