How do I uninstall High Sierra?

Erase the drive then install Sierra. This is the only way. Or you could try to fix your problems in High Sierra.

Possible Fixes for High Sierra

You should try each, one at a time, then test to see if the problem is fixed before going on to the next.

Be sure to backup your files before proceeding if possible.

1. Shutdown the computer, wait 30 seconds, restart the computer.
2. Resetting your Mac’s PRAM and NVRAM
3. Reset the System Management Controller (SMC)
4. Start the computer in Safe Mode, then restart normally. This is slower than a standard startup.
5. Repair the disk by booting from the Recovery HD. Immediately after the chime hold down the Command and R keys until the Utility Menu appears. Choose Disk Utility and click on the Continue button. Select the indented (usually, Macintosh HD) volume entry from the side list. Click on the First Aid button in the toolbar. Wait for the Done button to appear. Quit Disk Utility and return to the Utility Menu. Restart the computer from the Apple Menu.
6. Create a New User Account Open Users & Groups preferences. Click on the lock icon and enter your Admin password when prompted. On the left under Current User click on the Add [+] button below Login Options. Setup a new Admin user account. Upon completion log out of your current account then log into the new account. If your problems cease, then consider switching to the new account and transferring your files to it - Transferring files from one User Account to another.
7. Download and Reinstall 10.13.1 High Sierra Update
8. Reinstall OS X by booting from the Recovery HD using the Command and R keys. When the Utility Menu appears select Reinstall OS X then click on the Continue button.
9. Erase and Install OS X Restart the computer. Immediately after the chime hold down the CommandandRkeys until the Apple logo appears. When the Utility Menu appears:

1. Select Disk Utility from the Utility Menu and click on Continue button.
2. When Disk Utility loads select the drive (out-dented entry) from the Device list.
3. Click on the Erase icon in Disk Utility's toolbar. A panel will drop down.
4. Set the Format type to Mac OS Extended (Journaled.)
5. Click on the Apply button, then wait for the Done button to activate and click on it.
6. Quit Disk Utility and return to the Utility Menu.
7. Select Install OS X and click on the Continue button.

You will have to use your TM backup of the system you had before unless you have a previous system still showing in your purchased apps. that you can download. Sierra is no longer available to download.

i've got a truckload of related printing problems; frustrating in the extreme. is Apple saying anything about they're doing on this front and when? in addition to being polite it would be useful to know whether one should sit this out and wait for the fix/es, or go through the drama / trauma of uninstalling High Sierra

and now i can't even post the following question / issue?!

similar to the experiences of others i have lost all of my installed printers on my 13" MacBook Pro

any attempt at adding a printer results in the function beachballing and freezing, requiring a forced quit to close out

i had (unfortunately) updated my 11" MacBook to High Sierra as well. it is only on v10.13.1 though and, following a tip in another question with posted answers, i succeeded in being able to add a printer by entering its IP address. i have just succeeded in printing a test document this way (yay!)

do we have any information on Apple's response to this issue - which has obviously been around for some time - and what is intended to address it and when? i would prefer to avoid all the drama associated with reinstalling Sierra but the status quo is all but unworkable

#frustratedmuch