Thats why we are here to support and honestly, flashing Klipper is more difficult:
- If you power the board by USB, usually no need for +3.3
- RST usually not needed as well
- Remove Power from the board
- Connect:
- GND to GND
- DIO to SWDIO
- CLK to SWCLK
- Press and hold the BOOT button
- Power the board
- Release the BOOT button
- Flash with the flasher of your choice
The only thing I’m unsure about if you need to specify an offset in the flashing tool or if the offset chosen in make menuconfig is already taking care of it. Also not even 100% sure if you need to use BOOT when using the SWD interface.
If it was my board, I’d simply back it up and try it but I do not want to give any half baked advice.
Edit:
You might even be able to flash it with stmflash directly by connecting the RPi TX / RX pins to the STM/GD RX / TX pins or use an USB TTL adapter like described here: CanBoot: Flash BTT SKR 1.3 / 1.4 / 1.4 Turbo