[balinor]

Actually if you just want to remove certain ones, the above solutions won't work. This will require some php editing. Open up include/search.php and you'll see these lines:

"productcode" => func_get_langvar_by_name("lbl_sku"),
"title" => func_get_langvar_by_name("lbl_product"),
"price" => func_get_langvar_by_name("lbl_price"),
"orderby" => func_get_langvar_by_name("lbl_default")

Comment out the ones you don't want using a # in front of them.