1. Download the attachment and extract it to a fold at your choice.
2. Place the two .dll's in the game folder: \Steam\steamapps\common\Tom Clancy's Rainbow Six Siege.
3. You're done! Enjoy!
Notice: Note that these can get your account banned
Use them at your risk.
Adding to that, read the following:
when using this for more than a year, it will not unlock anything anymore so you'll have to re-download it and put it in your game directory when that year expires.