This can be easily done on the Escalation contract, called "The Sigma Illusion". You'd need to do the mission five times, each time with an increasingly difficult complication. For Level 5, the conditions are:
- Kill the chef with melee
- Hack the laptop on Level 6 of the mansion
- Hide all dead bodies with 90 seconds
- Do not pacify anyone
- Guards see through own disguises
Completing the steps below will fulfil all the above. You can basically repeat the steps for all levels of the mission if you so desire.
Planning:
- Start at the location "Undercover as Security Staff"
- Swap the coin out for a lock pick
Once mission begins, exit blend (
), and run very quickly to your right, then left, and then head into the doors at the end of the path. The guards will get suspicious, but just ignore them, and keep running. They won't chase if you disappear quickly.
In the room, go to the laptop, and hack it with
. Wait 20 seconds for the hacking sequence to complete. Unlock the door right beside the laptop with your lock pick. Escape through the next room, and climb through the windows.
Run towards the dome-shaped structure, and drop down to the level below. Enter the first door on your left, and you'll be in the observatory area. Head towards the stairs, and take one level down. Enter Francesca's room (this is where you seduce, and poison her if you follow the Golf Coach opportunity), and climb through the toilet window.
You'll now be near the outdoor dining area beside the kitchen (this is where you poison Caruso if you follow the kitchen hand opportunity), and your target should be walking towards the cliffs if you're doing it right. Sneak past the guards, get behind the chef, and subdue him by holding
. When the prompt to snap his neck appears, press
to do so. Take his disguise, and dump him into the nearby container.
You can now make a run for the exit. It should take around three minutes to do all the above if you're familiar with the mission. I've played through it several times, and this should be the fastest way to fulfil all the conditions for the contract.
Here's a video of the above - apologies for the long loading screen in between. I recorded it with Xbox DVR, and the game does take forever to load. You can skip to 1:48, which is where the mission actually begins.
PS: If you want to get a higher score, you can try to out run the earlier guards even faster so as to avoid a suspicion. You can also avoid the CCTV near where you kill the chef by sneaking and hugging the left walls. Take note also that when escaping, there's another CCTV to the left wall of the two guards near the red car - hug the left wall, and sneak run to the bushes near the two guards at the main door to avoid this. I replayed the mission ensuring that I did these, and ended up with over 189,000 points.
Update May 20th, 2016:
I've added a new video below for another easy mission to complete 5. The mission is "The Scarlatti Covenent".
Conditions:
- Kill Geovani Anselmi in the Priest Disguise
- Kill Fabio Pavione with an explosive
- Complete the mission in three minutes
- No pacifications
- Do not be caught on CCTV, or erase all evidences if caught
Preparation:
- Start at Church Morgue
- Swap the Coin out for a Lockpick
- Swap the Fibre Wire out for a Proximity Bomb
- Leave a Proximity Explosive Duck at the ICA Pick-up in the Sewers
Enjoy.