Hitman mod

Hello! How do you make a mod idea Hitman? That is, the ability to make a quiet murder wearing corpses etc. You can also implement sound from thrown objects, which will hear the NPC. I loved Hitman Absolation (and the whole series) and would like to see some of my favorite features in GTA IV. Hitman 6 to wait for a long time, I hope you liked my idea. Thank you in advance)



(Sorry for my English.  I'm Russian