Here's a 100% save game download: http://www.gtagaming.com/downloads/g...misc-mods/2740
and first you need XLiveless: http://www.gtagaming.com/downloads/gta-iv/tools/2408
Download XLiveless, take the xlive.dll file and put it in your root GTA IV directory (if youre not using steam thats C:\Program Files\Rockstar Games\GTA IV\)
Then download the save game and put it in C:\Documents and Settings\USER\Local Settings\Application Data\Rockstar Games\GTA IV\ . The folders might be hidden so you have to turn on hidden folders.
Using XLiveless stops multiplayer from connecting. this is the only way to use savegames because normally the saves are stored with your Live account.