Bukkit

First of all, open your config.yml
Now it should contain those values:

message: 'Your donation message here'
prefix: 'YourPrefix'
topdonors: 'Your donators'

Now what you want to do is
underneath the topdonors: value
add the following:

- Your donator here
- Your second donator here
- Your third here

And so on till you got all your donators listed down
Now the topdonors should look like this:

topdonors:
- donator here
- donator here
- donator here

(if for any reason you do not have the quotes ' ' there, please add them if you want to use color codes ( & ))

• And now just update the plugin and start the server and done!
  
• Remember changing anything in the config, ingame you must type /donate reload