Install OpenIV if haven't already. 
This is a much shorter boot intro than the gta 5 one. 

1. Run OpenIV and select GTA 5 for windows. 

2. Click on Update folder. 

3. Click on update.rpf. 

4. Click on x64 Folder. 

5. Click on Movies folder. 

6. Right click the file in there and replace with the Warriors one. 

7. Add me on steam if you want - Krypteh

The Warriors Boot Intro for GTA 5 'Rockstar Games'

 Download

CC gta5-mods.com