function.php woocommerce and bootstrap

Hi all,

I have two questions, hope someone can help me.

1)
sudo :
add filter -> function override checkout feilds -> Condition -> unset -> return

add_filter( 'woocommerce_checkout_fields' , 'custom_override_checkout_fields' );
function custom_override_checkout_fields( $fields ) {
	if( $fields['billing']['customertype'] == "selectfromdropdownboxvalue" ) {

		unset($fields['billing']['customer123']);
	}
			return $fields;

}

my question is, how can i get the value 1 or 2 from the dropdown box ? what should i be looking for ?

section question is, can i manupulate the bootstrap colums from functions.php ?