Manual of Sega GG HDMI LCD Mod Kits (Single Chip)
You don't need to trim the shell if you haven't purchased the HDMl version
After remove the components
Soldering 200 Ohm resistor on the R25.
Soldering the C39 and C40 with 10pF capacitors.Connect the R13,R14,R15,R16 with Tin wire or 0 Ohm.
Welding the FPC ribbon cable on the motherboard
Connect BUT1 to c38, BUT2 to C37,BUT3 to C36.Connect R23 to T10.
Replace R34 with 0 Ohm/bridge.
Connect the R to M41.L to M42.
Connect the BK,SMs, 5V as shown.
Place the SEGA motherboard into the shell and connect the flex cable as shown below.