The buttons are very easy to install. If you get Snap-in buttons (Sanwa OBSF-30s or Seimitsu PS?14?Gs are the two most common), you only need to snap the buttons into place by pushing them into place. Screw ins (Sanwa OBSN-30s or Seimitsu PS-14-GNs) are only different in that they need to be screwed into place with a threaded washer. Snap ins are already present, and to release, simply unplug the stock quick disconnects, and use a small flathead screwdriver to push the two tabs inward and upward, and replace with your preferred buttons. Then replace the quick disconnects accordingly. (order does not matter. As long as the same color wire is on both ends, it will work). The major difference between Sanwa and Seimitsu buttons is that Sanwas are HIGHLY sensitive, while Seimitsu require a bit more force to activate. I prefer seimitsu buttons because Sanwa are too sensitive for my taste. I could rest my finger on a button by accident and cause an accidental input. It just depends how sensitive you prefer your buttons.
Joysticks are also easy. Sanwa JLFs are the “real” stick that the stick joystick is a knockoff of. Seimitsu LS-32s are another brand of joystick, but are not the same as the stock joystick. The feels are a bit different, but I use sanwa JLFs because they have an octagonal gate option. If you’re used to the feel of the stock stick, you’ll want a square gate (already included on all Sanwa and Seimitsu joysticks). Worth an extra $5 to try an octagonal gate, if you’re interested in gate that has a corner for each direction. LS-56s have this option, but they’re a bit heavier than LS-32s or JLFs. Order a version that doesn’t include a wiring harness, you do not need it (LS-##, but not LS-##-01 For Sanwa, JLF-TP-8YT-SK). First remove the balltop from the stock joystick (Place a large flathead screwdriver at the base of the stick on the inside, you’ll likely be able to tell where, then twist off the stock balltop. NOTE: This fits Sanwa JLFs, if you don’t want to order a custom balltop, keep the stock one, Sanwa joysticks ship without balltops, Seimitsu sticks, however, come with your choice of color balltop free of charge) After removing this, remove the wiring harness (It’s glued on, but it will come off), and then unscrew the wiring harness. The stock joystick will come right out. Use the stock screw to screw back on the new joystick (should have a mounting plate included. If it does not, use the stock mounting plate to replace it), and plug the wiring harness back in. If you’re using a Sanwa JLF stick, plug in the wiring harness the way it was (Metal tabs exposed), if using a Seimitsu stick, turn the wiring harness 180º, and plug in (metal tabs not exposed). Completely solder free, and you’ll love the new responsiveness.
Also, I recommend a bit of hot glue on the wiring harness. I had it slip out a bit every once in a while, and it was enough to disconnect it. It was annoying, but the stock wiring harness just isn’t a perfect fit.
All you need is a few screwdrivers. One phillips head to open up the case, and remove the mounting plate. One small flathead to pop out the stock buttons, and one larger one to remove the balltop.
Good luck, and enjoy some real arcade parts. ;D