Mission tip: < To dual wield the pistols, first drop one and equip the other one and then grab the dropped pistol back.
Mission guide: The last mission will start immediately when choosing the level from the main menu.
And there is no map for this level so I'll try to tell as much details as possible.
Follow the hallway left and open the door.
Take out the guard with the UZI (the gun you took from the previous level).
If you want take the guards pistol which is the favourite gun of 47 (besides the W2000 sniper rifle).
Also grab the shotgun in the locker besides the desk of the guard.
Continue through the door and go left when possible and a introduction cut scene of your clone 'brothers' will start (see pic below).
Go all the way back in the hallway and take out the last guard in the game around the corner after opening the door.
Grab the guard’s pistol if you like to use it at the end of the level if you want.
Look in the locker behind the guard you just took out and grab the body armour, shotgun rounds and the UZI rounds if you like.
When done the chance is big that your clone 'brothers' are searching for you right now.
Just stay in the room you are now in and take them out once having a chance with use of the 'look around corner' key (see pic below).
If I’m right, then there are ten clones to deal with but there are eleven on the picture below but that is something for the second game.
So count the body's and when you took out ten clones then drag one to the scanner you saw at the cut scene.
The scanner is to the north from where you are now and a cut scene will start once you enter the scanner area.
Note: If you don't drag the body in the scanner and use 47 instead then the room will lock and gas will pour into the room which will kill 47.
Once done scanning then move forward and choose your weapon.
I personaly using the dual wielded pistols to take out the proffessor which is very easy (see pic below).