Hmm.... seems nice and simple. If you have any knowledge of a text editor + ftp program....
Edit /Sources/shop/items/IncreaseKarma.php
Change:
class item_IncreaseKarma extends itemTemplate
to
class item_DecreaseKarma extends itemTemplate
and....
db_query("
UPDATE {$db_prefix}members
SET karmaGood = karmaGood + {$item_info[1]}
WHERE ID_MEMBER = {$ID_MEMBER}", __FILE__, __LINE__);
return 'Successfully increased your Karma by ' . $item_info[1] . '!';
to
db_query("
UPDATE {$db_prefix}members
SET karmaBad = karmaBad + {$item_info[1]}
WHERE ID_MEMBER = {$ID_MEMBER}", __FILE__, __LINE__);
return 'Successfully decreased your Karma by ' . $item_info[1] . '!';
~~~
Then save that as DecreseKarma.php and upload it to where all the other items live. I'm not going to bother to make a package for this because there's probably not that great of a demand.... Sorry.