- enabling developer settings first, enable oem unlocking
- shut down your phone
- hold volume up and down at the same time and while holding them plugin your charger.
- Your phone now should show a green screen with instructions to unlock the bootloader.
- Just follow them and after the unlocking your data should get wiped. After that your device will boot up and land in setup screen.
- Do not setup anything, just skip as much as possible, because your phone will get wiped again.
- Enable developer settings and make sure oem unlocking is greyed out and enabled. (If it does not show up, connect to a network first!)
- Download twrp https://github.com/Grarak/android_device_samsung_a70q-twrp/releases
- Push the recovery.img file you just download for TWRP to your phone
- Open Magisk Manager and hit install and patch a file.
- Select recovery.img and Magisk should start the patching process.
- Once Magisk is done, boot into TWRP.
- Backup your boot partition first and afterwards go into install and then hit install image on the bottom right of the screen.
- Select /sdcard/Download/magisk_patched.img and install it to boot.
- Now reboot and Magisk should work.
- If you run into issues after this, go into TWRP and restore the boot partition you backed up previously.