This mission is given by Tam Brodie.
"Jimmy! Jimmy, it's me, Tam. Eddie Fu found out what we did to his brother. The cheeky fucker just called, told me he's sending out two Chinese assassins to fucking kill me. Would you credit the nerve on that one? I don't know any of this ching chong kung fu shit Jim, I need you to take these pesky little fuckers out for me. Would you do that?"
This is one of the most complicated missions in this DLC. It involves a lengthy firefight with both the Triads and police, so be well stocked on ammo and in full health before you start. From the mission start in Highbrook drive east to the first assassin. There's no real access other than a frontal assault so park your car on the street to use as cover while you kill the Triads guarding the entrance. Once inside the compound, make your way to the back yard where you will find the first assassin at the bottom of the hill standing behind a covered deck.
Once the first area is cleared hop the wall into the adjacent yard and start clearing out the Triads there. The assassin here can be hard to get a clear shot at. He's located on a mid-level covered balcony that has no access from the outside, which gives him a very good vantage point to take shots at you while he stays in cover. If he won't come into the open you can lob a grenade or molotov onto the balcony which should take him out.
Once he's dead you can either stay and finish off any remaining Triads or just head to the safe zone and end the mission.