I would like to install the macOS bigshur

Hi jayleonb,

Thanks for posting your detailed specs! As mentioned by Ozzie1910, unfortunately you will need to erase your Mac in order to downgrade to macOS Big Sur. You will need a 16 GB or larger flash drive for the downgrade.

Prepare - change secure boot and allow booting from external media

Your Intel-based Mac has the T2 Security Chip inside. For better security against attackers, your Mac only allows recent versions of macOS to be installed, and it doesn't allow booting from external drives by default. This will need to be changed for the downgrade process:

1. Start up in macOS Recovery: Hold down Command-R as you power on or restart your Mac.
2. If you're prompted for an administrator password, enter it to continue.
3. At the top of the screen, select Utilities -> Startup Security Utility.
4. Authenticate with your username and password if prompted.
5. Set the Secure Boot setting to Medium Security (to allow the downgrade). At the bottom, select Allow booting from external or removable media.
6. Save your changes (if a relevant button appears), then quit Startup Security Utility and restart your Mac.

Prepare - create the macOS Big Sur bootable installer

Once the security settings are changed, you will need to stamp a copy of macOS Recovery for Big Sur on a flash drive. All data on the flash drive will be lost. To do this:

1. Download macOS Big Sur from this article: How to get old versions of macOS - Apple Support
2. Connect a 16 GB flash drive, and open Disk Utility (in Applications -> Utilities).
3. In Disk Utility, select View -> Show All Devices.
4. Select the top level of the flash drive and click Erase. Choose these options, then click Erase:
   1. Name: MyVolume
   2. Format: Mac OS Extended (Journaled)
   3. Scheme: GUID Partition Map
5. When the erase is finished, quit Disk Utility.
6. Open Terminal, located in Applications -> Utilities.
7. Paste the below command in Terminal (use Command-V to paste) and hit Enter (Return). Enter your password when prompted; Terminal will not show anything as you type your password. The process is complete when Terminal informs you that bootable media is now available, and your username appears at the bottom of the command prompt.

sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --nointeraction

Erase and downgrade your Mac

1. Turn off Find My Mac in System Preferences -> Apple ID -> iCloud.
2. Back up all of the data that you want to preserve. It will have to be transferred back manually once the downgrade is complete.
3. Connect the bootable installer you made earlier.
4. Restart your Mac while holding down Command-R. Release the keys when the Apple logo and a progress bar appear.
5. If you're prompted for an administrator password, skip to step 8.
6. At the top of the screen, select Utilities -> Terminal.
7. Type "resetpassword" without the quotes, and hit Enter (Return).
8. At the top of the screen, select Recovery Assistant -> Erase Mac.
9. Follow the onscreen instructions to erase your Mac.
10. Hold down the Option key as your Mac restarts. Release it when the bootable installer appears (Install macOS Big Sur). Select it and hit Enter (Return) to boot from it.
11. Follow the onscreen instructions to install macOS Big Sur.

After the downgrade

If you made a Time Machine backup of your data when you were previously running macOS Big Sur, you can transfer the data from that backup using Setup Assistant. Otherwise, you will have to transfer your data back manually.

Try to set the Secure Boot setting back to Full Security if possible. See the first section at the top, but choose Full Security, not Medium Security.

Do you speak Spanish? You know that to downgrade your Mac to a older macOS version you have to erase the hdd?

backup all your personal info like documents and other things that you don’t wanna lost , or drag them into the iCloud Drive , everything will be save it

To do a downgrade restart your Mac while holding down CMD-OPT-R when you see a spinning globe 🌎 release the keys select your wifi type your passcode and wait for the macOS utilities then select disk Utility once u get in there find your ssd or hdd by the name like apple ssd something like that, if you don’t see go to the menu bar in View then select show all devices then select your SSD then click erase in the name field you will see untitled change it for Macintosh and in the next field select APFS then in the scheme select Guid partition map then erase , once your ssd it’s erase back to macOS utilities select install macOS I think you will get macOS Big Sur

Ozzie1910 wrote:

To do a downgrade restart your Mac while holding down CMD-OPT-R when you see a spinning globe 🌎

Holding down Option-Command-R at startup will request the latest version of macOS Recovery - the one that includes the Monterey installer, not the Big Sur installer.

What’s your Mac 💻 model ?note all Mac from 2013 and lower are not supported to install macOS Big Sur

Go to system preferences software updates click on it and wait there you will see a new updates could be macOS Big Sur or macOS Monterey