How to install DietPi directly on Raspberry

Hello.
I have DietPi 4 and run Raspberry OS on SD Card. Unfortunately I don’t have SD Card Addapter to Flash DietPi. How can I install DietPi OS directly on my Raspberry?

https://dietpi.com/forum/t/create-a-dietpi-based-distro/3127/2

Hi,

Pls follow following instructions to install DietPi on top of an existing Raspberry OS installation. Keep in mind, this will remove existing software installation https://dietpi.com/docs/hardware/#make-your-own-distribution