- Disconnect the printer from your Mac.
- Uninstall current printer (if possible also the driver) and reboot.
- Download and install the driver for LBP3000 "CAPT Printer Driver & Utilities for Mac V10.0.0 [macOS 10.13/10.14" from here https://www.canon.com.au/laser-printers/laser-shot-lbp3000/support
- Download the patched files http://andreaplanet.com/useful-uploads/patched_driver_lbp2900_for_mojave.zip
- In the Finder Menu do "GO"->"GO TO FOLDER..." as shown in the screenshot a few posts above.
- The Finder will ask you for a folder. Paste the text "/Library/Printers/Canon/CUPSCAPT2/Bidi". Note the initial slash / before Library.
- The Finder will show you the contents of the folder. You should find there a file called captmoncnab3. Replace it with the patched file contained in the downloaded file patched_driver_lbp2900_for_mojave.zip. You must replace an existing file. If you are not replacing an existing file then you are not patching it correctly. You need to give the Administrator password because it is a system file.
- Then again, in the Finder Menu do "GO"->"GO TO FOLDER...". Specify the folder "/Library/Printers/Canon/CUPSCAPT2/cnaccm". Note the initial slash /.
- You should find there a file called CnAC28B9.DAT. Replace it with the patched file contained in the downloaded file patched_driver_lbp2900_for_mojave.zip. Again you must replace an existing file else it won't work.
- Reboot.
- Connect the LBP2900 to the USB Port and in the System Preferences add a Driver for it specifying the Canon LBP3000 Driver.
I did this installation for a friend, I neither have mojave nor that printer, so my help is limited now.
I know that it would be more convenient to have an installer for all this. There is an PKG installer/patcher for the old drivers but it doesn't work anymore because the new Canon drivers changed the installed path slightly.
