Oh OK thanks I, is there a guide I want to make a project
Not really much to it. The SoC does everything so you just need that and the RAM. This trim cuts off all power, audio, and controls. No sense trimming more than this because the cart slot is wider and the cartridge itself is taller.
Feed the SoC, cart slot, and LCD connector, 2.5v, 3.3v, and 5v and then patch any disconnected rails on the remaining board and that takes care of power. I made a custom PSU for mine but I didn't put any effort into efficiency since this was just a proof of concept. Ideally you'd want soft latching for the 2.5v and 3.3v rails on the power switch and then the 5v rail latching on the SoC VCNT pin. Or just switch all three with the power switch and then the sleep mode doesn't work properly in the four games that actually support it. If you only want GBA mode, you can omit 5v entirely though most of the IPS screen kits require 5v input anyway unless you bypass those regulators too. Depending on your PSU, you may need extra capacitance hence the "power cleaner" on mine.
Screen connector is intact as is so long as you run 5v to it again for the LCD. Stock screen on 40 pin needs that extra IC to the left clock crystal and both 40 and 32 pin models need the other two voltage rails, -13v and 15v so just stick with an IPS kit or consolizer kit.
Audio is standard PWM out of the SoC. Connect up your own amp for whatever your needs or relocate OEM amp if you want. That's sound.
Controls are all just common ground and one pin per on the SoC per button (no diode matrix array like the Pocket and original model). insideGadgets sells on occasion a wireless RF transmitter and receiver kit you can wire in or you can just do like a SNES controller type thing that the consolizers do. And that's controls.
There are schematics for this console as well.