1. Run the original LaunchGTAIV.exe to pass the release date check, be connected to internet.
2. Now copy the crack (LaunchGTAIV.exe I provided) to the GTA IV installation folder.
3. Disconnect from the internet.
4. Copy the cracked paul.dll into game root folder.
5. Run LaunchGTAIV.exe (one you've replaced, the cracked one).
6. Now Social club launches asking u to sign in.
7. Start social club in offline mode.
8. The game launches.