How do i install real linux on a chromebook?

So I am buying my new Chromebook, and since chromeOS is closed source I want to install Linux. I found online guides to it, but they were all for Installing the Linux (Beta) Feature AKA Crostini on it, which Is a built in feature. I actually want to remove chromeOS and install Linux, specifically ubuntu. My Chromebook Is: Acer 315 Celeron N4000 4GB Ram, 32GB eMMC (CB315-3H-C2C3). I originally wanted to install Windows, but it was only available on the CB315-2H Model, and I had the CB315-3H Model. The chromebook is not compatible with MrChromeBox’s Custom UEFI Bios/FWScript.