How would i Undo this

Code:
# Add the following to your database via Zen Cart Admin.

# NOTE...IF YOU USE A DATABASE PREFIX YOU MUST ADD IT INTO THESE TABLE UPDATES - FOR EXAMPLE:

# If your db prefix is zen_, then change 
# CREATE TABLE `free_gifts` ( 
# to 
# CREATE TABLE `zen_free_gifts` (




CREATE TABLE `free_gifts` (
  `gift_id` tinyint(4) NOT NULL auto_increment,
  `threshold` mediumint(9) NOT NULL default '0',
  `products_id` mediumint(9) NOT NULL default '0',
  PRIMARY KEY  (`gift_id`)
) TYPE=MyISAM;

insert into configuration (configuration_id, configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, last_modified, date_added, use_function, set_function) values (1200, 'Gifts Image Width', 'GIFTS_IMAGE_WIDTH', '90', 'The pixel width of heading images', '4', '25', now(), now(), NULL, NULL);
insert into configuration (configuration_id, configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, last_modified, date_added, use_function, set_function) values (1201, 'Gifts Image Height', 'GIFTS_IMAGE_HEIGHT', '100', 'The pixel height of heading images', '4', '26', now(), now(), NULL, NULL);
ALTER TABLE `products` ADD `products_carrot` tinyint(1) default '0' AFTER `products_status` ;