I apologize for the length of this post but it takes this much to explain the process. Im sure I have left something out and if you have questions, send me a PM and Ill clarify if I can.  IF you decide to make the fuel pressure regulator adjustable the info below will be helpful.  The pics will be helpful if you just decide to rebuild the throttle bodies, its not difficult at all.  The pressure adjustment tool in the photos is a $50 bought one belonging to a buddy.  I made mine from a piece of copper tubing and an old carburator adjustment tool with a flex shaft on it.  You may decide to balance your throttle bodies which may help performance as well. It's important for the throttle bodies to operate exactly at the same time and to the same degree. This is not a difficult task but does take a little time.  I have a step by step procedure for this also if you are interested. OK, here goes.

Making the fuel pressure adjustable is not rocket science or really difficult, it just takes a little time and patience to do. You will need to order a throttle body rebuild kit before you start because you will be disassembling parts with gaskets between them. The kit is available from Ecklers as well as other suppliers. Once the gaskets are disturbed, you will need to clean the surfaces and install new gaskets and "O" rings. Pay careful attention to how everything goes together so you will know how to reassemble. Taking pictures as you go is a wise idea. 

First off, you will NOT need to remove the throttle body bases from the intake. You will need to remove the injector "pods" or "towers" from the bases. This can easily be one with the bases on the car. You will need to remove the 5 screws that hold the top of the tower to the tower itself. All of these screws are not the same length, keep track of which screw came from where. Once the 5 screws are out, you may need to tap the top the cover with a screwdriver or small hammer to jar it loose from the tower. After it is loose, remove the top and attached fuel fuel pressure regulator. Removing the injector itself is easy, just use a screwdriver to pry it out, here you see me using ahandle of a pair of pliers as a fulcrum for the lever. Pay PARTICULAR attention to the "O" rings and metal ring. These MUST be installed exactly right when you reassemble. Getting the injector back into its place with the spacer and "O" rings will be a difficult chore. It MAY be possible to leave the injector in place but scraping off the old gasket will be difficult but there are "O" rings and a screen filter on the injector itself that you will probably want to replace. You will next need to remove the the fuel pressure reguator from the lid. This will be done by removing the 4 screws that hold it in place. There is a STRONG spring in the regulator that mut be contained as you unscrew the 4 screws. This can be done either by mechanical clamps or with your hand . The spring is strong but not to the point that you cant hold it. Release all the parts that are inside and day attention to how the parts are arranged.  Be aware that the diaphrams are different for the drivers side and passengers side throttle bodies. When disassembling the pressure regulator DO NOT turn the screw on the pressure adjustment until everything is back together and you have a pressure gauge installed.  If the screw is left at its original position you should have the same pressure 11-12 pounds after reassembly as when you disassembled it. There is a "plug" in the bottom of the regulator that blocks the adjustment of the fuel pressure.  This plug must be removed by using a punch to drive it off, it will not give much resistance. Once the plug is removed, the regulator can be reassembled just as it was before. With the plug removed, you will be able to get to the adjustment stud. You now should be able to see how the tool works. By turning the stud, it moves the washer inside of the regulator and increases or decreases the spring tension inside of the regulator. Once the tower is reassembled onto the base and the injector is reinstalled, the tool is used to reach under the throttle body, engage the stud and adjust the pressure. The pressure you are looking for is 14 - 14.5.