At the beginning of the game, you get a call telling you to get to a payphone nearby. These are the Assassination Contracts, and when you have completed the first, the rest are unlocked at different points in the storyline. You MUST complete them in the same order - for the third one to activate, you must have completed the second, and so on. There are five in total.
Road Kill
The call for this mission will be made after the mission "Jury Fury", early on in the storyline.
You learn that your alias is Mr. Teal, and the mystery man on the other end will be handing out the jobs. Your first target is Carl Pearson, a pizza delivery boy, and you need to take him out before he finishes his fifty deliveries. You are given quite a lot of time to do this mission, so if you brought a car, you can simply knock him off the bike, and kill him to have done with it.
Mission Passed: $500
Waste The Wife
The call for this mission will be made after the mission "Mall Shootout", still early on in the storyline.
The target this time is a Mrs. Dawson, who is shopping in a Jewelry Store nearby. When you park up outside, you are given more information. You must damage her car until the point of it flaming, and then get out of there. It must look like an accident, so no weapons can be used either. Get a fast car to match the speed and acceleration of her Comet sports car, and then start ramming her off the road. When the car starts flaming, drive away from her, or keep your distance.
Mission Passed: $2,000
Autocide
The call for this mission will be made after the mission "The Fastest Boat", slightly later in the storyline.
The client has a number of targets, all of them involved in a planned robbery here in Vice City. You can take the sniper rifle, Micro-SMG and a PCJ 600 nearby to help with this mission. You have nine minutes to take down all the targets. The first, Mike Griffin, is working on a billboard nearby, and it's nothing like a sniper bullet that will take him out.
The next target is Dick Tanner, a DB-P Security Guard. When you approach, he will make a break for it in a Securicar. Cause enough damage to get Tanner out, and then take him down. The next two targets are Marcus Hammond and Franco Carter, in Vice Point. They are both in a Bobcat, and when you alert them, one will make a getaway whilst the other one will attack you on foot. Aim for the passenger side when you attack, as it is pretty obvious that the assailant on foot will be the passenger. You will then have to take down and kill the driver to finish off this part of the mission.
There are two more targets out of the six we have to go for. Nick Kong will be cruising off Washington Beach in his boat, and Charlie Dilson will be cruising on his motorbike in Ocean Beach. Get a car, and snipe Kong on his boat, before hunting down Dilson, knocking him off his bike and killing him.
Mission Passed: $4,000
Check Out At The Check In
"Mr. Teal" is given the information openly this time, instead of the regular "taped under the phone" business. The mystery has had a Sniper Rifle hidden to the right of the payphone, in order to perform another hit. The plan is like this - a woman will be found above the check-in desks, wandering through a crowd of people, and will ask someone the time. You are then to kill the person she asks, and retrieve the briefcase, taking it to the AmmuNation in Downtown.
Get the Rifle and watch out for the woman, who will be marked by an arrow icon. When she asks that person the time, watching your Distance Meter, kill him and his bodyguard and retrieve the case. Go back outside, get your weapons back, and take the briefcase to the AmmuNation with a 2-Star Wanted Level, and dodging the attacks from the associates of the person you killed. A good idea may be to bring the Maverick you can access on the top of the Vercetti Mansion to the Airport, landing it in a safe place, and flying over.
Mission Passed: $8,000
Loose Ends
The call for the final Assassination Contract will be made after the Asset Mission "The Shootist".
The final Contract is the most challenging. You have to fight your way through suit-and-tie thugs with SMGs through this courtyard, onto the roofs of the buildings, across The Cherry Popper Ice Cream Factory, and onto the roof where you have to pick up merchandise. It then needs to be dropped off at the helipad at Escobar Intl. Airport.
There will be a number of thugs around the courtyard, and hiding on the rooftops. Take cover and try to spot them all, and then kill them. That is the only real information I could give you - be vigilant. A group of thugs will be guarding the merch, so beware of them when you pick it up. Use the Maverick on this roof, and then fly down to the drop-off.
Mission Passed: $16,000