Some details you must remember:
-Your solder skills must be advance or medium-advance to attempt this.
-If you try to do it with your razor remember that you will void your warranty with SparkFun.
-The same with ArduIMU, if you can't do it i will for you (free of charge).
-Not all the ArduIMU's flats have high pass filters, please double check. Check if the HP resistors are already gone.
To remove the capacitors and the resistors is pretty easy. First try to set the highest temp possible in your iron, then just apply heat in any of the side of the capacitor/resistors, the heat will spread in both ends melting the soldering in both sides, then just push it carefully. Try not to apply to much pressure or you may blow away the pad. I recommend to practice with the resistors first (the black ones), because if you blow away the pad it really doesn't matter (are not needed anyway), then try later with the capacitors (the brown ones), very, very carefully.
Now you must make a bridge in the capacitor pads. There's many ways to it, use any wire or piece of metal to make the bridge and apply soldering to keep it there. I used breadboard cable.
The next hi-res pictures indicates which components you must remove, the red arrows are the resistors and the yellow/green arrows are the capacitors. Good luck!