The how depends on the phone model, but there are step by step instructions available for many. Eg https://www.xda-developers.com/google-pixel-4-root-magisk/ ht

The how depends on the phone model, but there are step by step instructions available for many. Eg https://www.xda-developers.com/google-pixel-4-root-magisk/ https://www.xda-developers.com/google-pixel-4-root-magisk/ Also, if the phone has a vendor supported way of unlocking the bootloader, it will typically also trigger a wipe / factory reset (presumably because to keep DRM enforcers etc happy).