How to delete a specific block in a Minecraft server?

My friend spawned in a bunch of pig spawners in a certain area but i can't find them. Is there a command that will specifically delete pig spawners only? My map is flooded with pigs and I can't get rid of them.

If it is a Bukkit server then you can install some Plugins that allows you to delete certain blocks. If it is just a vanilla server then you will have to use MCedit to delete it which is a pain in the ***.