1] You need bots ID (100 to 1000 might be enough). Therefore you need to create ID bots using Manual way just like you create Yahoo Id or use Yahoo Messenger ID Creator aka ID Maker. usually, the bots ID stored in notepad aka txt file with a format ID and password like this:
etc.. (upto 1000-10000 id bots)
2] You need Yahoo Boot Software that work properly.
3] Load you BotID in Yahoo Boot Software by selecting stored BotID in txt file and load in Yahoo Boot Program.
4] Select the Type of your Boot Option
5] Select / Type Target aka Victim Username or Yahoo ID
6] Final steps. Boot him! Done.
For better understanding, here I found Youtube Video tutorial how to boot in Yahoo Messenger.
Note: The ID maker used in the video above is not work anymore. You must find newest working ID boot and also Yahoo boot.