No client changes are needed, this should work just fine .. But keep in mind this is going to do all the orcs and goblins in every single zone everywhere.
If you just want to be zone specific, well that's a bit more complicated.
But essentially it would look like this
Code:
UPDATE
`npc_types` INNER JOIN `spawnentry` ON `npc_types`.`id` = `spawnentry`.`npcID`
INNER JOIN `spawn2` ON `spawnentry`.`spawngroupID` = `spawn2`.`spawngroupID`
INNER JOIN `zone` ON `spawn2`.`zone` = `zone`.`short_name`
SET
`npc_types`.`race` = '54'
WHERE
`npc_types`.`race` = '458' and `zone`.`zoneidnumber` = 5
zone 5 being highold.. Anyway you can do this zone by zone if you like or use the query i posted before to do your entire database if that's what you want.
Morty