Um, the only tricky part was prying the needle up, I watched the Low and Mean vid on youtube and used their method of prying with a fork but it wouldn't budge. I gently rocked it back and forth and the glue that was holding the needle and round grey plastic cover to the internal "wheel" with the post on it (you'll understand when you remove it) the glue connection broke and the 2 pieces separated. After I got it out though, I used a dab of 2 part epoxy where OEM had put it so it won't come out again.
There's also a trick to "clocking" the needle when you press it back in BEFORE you hook it to the bike. Pressed all the way in, the needle will just spin 360*. If you pull up SLIGHTLY then cycle the needle with your hand, it will engage at the bottom and top stop. You want to set this so the needle points to 0 at the bottom. If you are slightly off, you can (while the needle is slightly pulled up when you were testing the stops) adjust it by spinning the needle "beyond" the stop...ie it basically moves the stop one way or the other. So, when it's set right, with the needle slightly pulled up, when you spin it to the left and it hits the bottom stop, it should be reading right on the zero. Tip: You don't need to completely remove the needle again to make this adjustment.
Just make sure before you put everything back together to plug it in and turn the key on, let the needle cycle and make sure it comes to rest at 0 before you put the electronics back in the case.
It's kind of hard to describe in words, hopefully that kind of makes sense.
Other than that, the shortest stubby philips head screw driver you have is necessary for the hardware that releases the speedo from the bike. Or you may be able to use a ratchet with an adapter for driver bits too.