To earn this trophy, you need to start and complete the Ulterior Motives mission.
When you start the game, you are given the option to play mission in Film Order or Selectable order. Pick Selectable. This way you can choose Ulterior Motives right from the start.
To start the mission, you have to hit the 'Mode Start' button near the middle of the table 3 times. Once you hit it the third time, you will have 10 seconds to choose a mission. For this trophy, pick 'Ulterior Motives'. As long as you do not drain the ball, the mission will not end. The mission is not timed, so take your time and line up your shots.
Once you have selected the mission, hit the same 'Mode Start' button again. This will light your ball on fire, which is necessary to complete the mission. Let the ball fall after being ignited and bounce off the right flipper in order to catch it with the left. This will make the next shot pretty easy once you get the hang of it.
With the ball on fire, shoot the ball up the far right ramp, labeled 'Burke'. When you hit this ramp, you will be taken to the mini-table in the top right. Use the right flipper to shoot the ball into the pocket in the top left of the mini-table. (Make sure the ball is still on fire when you do this. If the ball is no longer on fire (it is timed), hitting it into this top-left pocket will just drop the ball back onto the main table. If this happens, you can simply hit the 'Mode Start' button 1 more time to light the ball on fire again and hit the 'Burke' ramp. If you miss the top left pocket while still on fire, go back up the 'Burke' ramp and try again.)
Hitting the top-left pocket of the mini-table with the ball still on fire will start the two-ball multiball. This is where the most difficult (but not that difficult) part of the mission begins.
The two balls will be shot into the table from the launcher. You will have a short period of ball save, so try to take as many shots as you can while this is active. Your goal is to hit three ramps to defeat a Facehugger. These ramps are always in the same place. You need to hit the 'Hudson' ramp on the left, the 'Hicks' ramp in the center, and the lane to the immediate left of the 'Burke' ramp through the bumpers on the right side. You can hit them in any order, so hit them however you like. There will be flashing arrows indicating which ramps you need to hit. Remember, you have to balls in play and draining one or both of them will end the mission. Try to hold one ball in one of the flippers while using the other ball in the other flipper to hit the ramps. Once you hit all 3 ramps, shoot the 'Jackpot' elevator thing in the very center of the table. This will lock one of the balls and defeat one of the Facehuggers.
Hit these 3 ramps one more time with the single ball you have left and then hit the 'Jackpot' one more time to defeat both Facehuggers and unlock your trophy. The trophy unlocks as soon as you hit the 'Jackpot' for the second time.
Overall, this trophy is not too hard. I got it after a couple of attempts. Good luck!