heres a short DIY for all honda:
material: two-wire button, bosch type
relay 30/40 amps w/ harness
button: lets say theres black and white wire. ground the black wire.
w/ a relay:
85:white wire from button
86 and 30:12volt constant (white wire right next to starter wire)
70:blk/wht starter wire.
antitheft bypass is not needed
thats just an example, the S2000 button is probable diff, but you only need two wires.