Cloning hard drive to an external SSD.Link to setting up SSD as external boot drive:.IMPORTANT DISCLAIMER: Make sure you BACK UP your Mac with time machine before doing any of this! :) A quick search online will turn up using vmware or parallels for option #1. Here's a nice video tutorial to set up the latter option. If you're on a fairly quick Mac, moving from the SSD to the internal OS shouldn't take more than a minute. The last option requires you to log out from your account to then boot from the external drive, but will probably help you stay focused when you're working in Lightroom or Adobe. Option 2 below will require that you clone your Mac hard drive to and external SSD like the Sandisk Extreme 1Tb or any SSD with fast read write (1gb transfer rate) using USB 3 or USB C. Just make sure you have a fairly new Mac with ample disk space 500Gb - 2Tb and memory of 16 - 32Gb. CS 6 and other 64/32 bit software should run fine there and you can move between monterey and mojave easily. Then restore your backed up system from time machine on the virtual machine. Option 1: Backup your current system with time machine, install VMware or Parallels and install Mojave in the virtual machine. That said, there's a couple other options that will cost a little upfront but will allow you keep using your old Adobe software running. I don't use lightroom or photoshop enough make the $$ warrant paying their usage royalties. I too don't want to fork over adobe's exorbitant subscription fees. I'm in the same boat with my 2015 macbook pro 13".