Stephane is pretty ticked off. Somebody stole something of his and he clearly thinks the Red Coats had something to do with it. He's going to try and start trouble and it is your job to try and keep damage to a minimum.
Follow Stephane up the street and he'll start taunting a couple of red coats on the right side of the street. There are three constraints to this and each one is helped by being efficient. When Stephane starts taunting guards, get behind the rear most guard and assassinate him while their attention is turned to him. You should be able to assassinate him with no trouble and if you are quick, you may be able to assassinate the next guy without going into conflict. If not, have your pistol ready and shoot him to end the fight almost instantantly. There are at least five groups so if you do this for each group, you'll have your five assassinations and save yourself a lot of time.
After dealing with these two and watching Stephane get a crowd going, you'll go into a yard with two more guards. He'll taunt these two and you simply have to do the same as you did before.
Just beyond the yard will be a large group of four Red Coats. Pick one group and start the fight by assassinating both. Only one of them will be counted as low profile but you'll get rid of half the group. Shoot a third guard and (if you have arrows) switch to bow and shoot the fourth guard to end this fight quickly. Even then, with three of the four down almost instantly, killing the last one should be pretty quick. Just make sure you go for the tougher targets first.
You'll walk out into a street and a couple of Red Coats will be walking up the street towards you. Get behind them and assassinate them as best you can. Not far beyond them, you'll enter an alley and find two more Red Coats. This is the last group so wait for Stephane to taunt them. Assassinate them and shoot if you have to finish this section and meet all of the constraints.
When you come out of the alley, you'll have to direct Stephane to kill the man in the market. Use the LB/L2 button to do so and end the memory.
