How do I get Big Sur off my Mac?

How do I get Big Sur off my Mac?
How to downgrade from Big Sur step by step

Backup your data (pretty please)
Install macOS Catalina on a bootable drive.
Remove macOS 11 from hard drive.
Reinstall macOS Catalina on your Mac.
Restore data from backup.

How to downgrade from Big Sur step by step
  1. Backup your data (pretty please)
  2. Install macOS Catalina on a bootable drive.
  3. Remove macOS 11 from hard drive.
  4. Reinstall macOS Catalina on your Mac.
  5. Restore data from backup.
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