Download link: http://euploadfree.com/SheelaghWhidden4491/jailbreak
There is no special trick to making ASI scripts work in multiplayer. If you are running GTA IV v184.108.40.206 and have the latest ScriptHook, then you can use scripts in MP IF THE AUTHOR ALLOWS YOU TO. Some authors have disabled their scripts in MP, there is no way to change that. Do not ask about installing mods on your Xbox 360 or PS3 - there are no tools publicly available for that.