These instructions will explain the process for removal of the ECU on the Porsche 991.2 Targa models. These instructions differ from the Carrera, Turbo, and Cabriolet models because the bumper cover will require full removal. 
COBB Tuning would like to give a special thanks to BBi Autosport for assistance creating this document. 

Tools Needed

• Flathead screwdriver

• 3/8" ratchet

• 3/8" 10mm socket

• 3/8" T30 Torx Bit

• 3/8" T25 Torx Bit
• 3/8" T45 Torx Bit
• Masking Tape

Estimated Removal Time: 2+ hours

Instructions

Battery Disconnect and hood/deck/spoiler/Targa Top open

1. Make sure the car's coolant is cool and parked in a location where you can be comfortable leaving it undriven while the ECU is sent out for bench flashing. If the car needs to be moved or pushed while the ECU is not in the car, leave the car in the "N" Neutral position so you can push it. Failure to put the car in "N" Neutral before you remove the ECU will keep the car stuck in the "P" Park until the ECU is installed again. 
2. RAISE THE SPOILER ON THE CAR TO FULL UPRIGHT POSITION. Also, raise the Targa Top to about the half way open position. The button for this is located by the shift lever on the car. 
3. With your car in a flat level place, pop the hood AND DECKLID and remove the car's cowl piece covering the brake master cylinder and battery.  Once done, go ahead and unhook the negative terminal of the battery using a 10mm socket.  Make sure to pop the decklid prior to removing the battery terminal, or you won't be able to get the decklid open. This goes the same for the spoiler, as mentioned in the step above. 
   
   Failure to disconnect the battery before removing the ECU can cause significant damage to their delicate circuitry. 
   Failure to raise the spoiler before you disconnect the battery will require reassembly of the car so you can raise it again. 
   This procedure of removing the ECU does require removal of the coolant cap. If the coolant is still hot and pressurized, personal injury could occur. Please proceed with caution. 
   
   
   
   
   
4. Now that the Targa top is halfway open, the spoiler is up, the car is in "N" Neutral, and the hood and trunk are popped, go ahead and disconnect the negative battery terminal with a 10mm socket. 
   
   
   
   

   Engine Cover, Fans, and Inserts Removal
   
   

5. Put a cloth over the spoiler, nobody wants to scratch Porsche paint. Go ahead and remove the hard "insert" for the air intake tube and then "pop" off the engine cover. 
   
   
   
   
6. Now, "pop" out the fans and unplug the connectors on the backside of them. 
   
   
   
   
7. Remove the right side insert by "popping" it out. The left side will require removing the coolant and oil cap to get it out of the way. It is held down by a 10mm bolt. 
   
   gh
   
   
   

   Taillight Removal
   
   

8. Start by taping off underneath the taillight housing so to not scratch the paint. Each taillight is held on by two T25 torx bolts. Remove these and then the taillight can be pulled out. You'll need to press down on the housing and pull outward. Be sure to unplug the electrical connector. 
   
   
   
   
   
   
9.