I assume you have a 145 mph speedo head in your possession. Begin by removing the trim piece surrounding speedo head and warning lights (pull the piece out srtaight, it is held to the dash by clips). Pull it firmly , but be careful not to crack it. I don't know the exact socket sizes, but remove the 2 screws holding the covers that house the waring lights (one on each side of the speedo head, so a total of 4 screws). Remove the 4 screws holding the speedo head to the dash. The speedo head is now loose, but you cannot remove it just yet. Lift the hood and separate the upper speedocable from the lower speedo cable (usually with 2 pairs of pliers). The separation joint is next to and between the master cylinder hydraulic lines. Put a little dielectric grease on the outer protective sheeting of the upper speedo cable near the sealing rubber ring (on the fire wall), then push the upper cable towards the interior of the car. Back into the inside of the car, you may have to lower the steering column (4 bolts on the bottom. If you have to lower the steering column, you also have to remove the 2 screws that hold the DS lower AC vent in position. Once the column is lowered, pull the speedo head foward enough to get your hand behind the speedo head. If you cannot get you hand behind the speedo head, you may have to push on the upper speedo cable more (from the outside). Reach behind the speedo head and there is a clip that you must push in to release the speedo cable. Once you can remove the speedo head, gently lay it down on it's face and there is a small set screw that holds the VSS permanent magnet. Remove the set screw and separate the speedo head from the VSS magnet and take the old speed head out. Transfer the boost and tach gauge (from the old speed head assembly) to the 145 mph spedo head assembly and reverse instructions to re-install. I purchased a recalibrated unit from Kirban (sometimes thay have extras in stock).