I will be over-explaining in this 'How-To' since I have no idea what level of computer proficiency anyone reading it has.

•    This procedure will only involve the CORE files to make the game run.
•    Most games today (2021) are starting to exceed sizes from 60 GB to 160+ GB. =O
•    These large game folder sizes are getting pretty ridiculous and tend to eat hard drive space easily.
•    We do not play all the games we own all the time and need to be stored in a Secondary or even tertiary ARCHIVE drive that is terabytes in size.
•    Because Ubisoft Connect does not address this issue specifically and their out-of-date game launcher can not even perform this simple task (as STEAM can easily) it is up to us (the players) to do what the devs can't do in a single day of FIXING this issue.
•    When I say "drive" I mean mostly SSD or M.2 drives because if you are still using a mechanical hard drive then you have more problems than just game file storage... UPGRADE ya cheap bastage! lol
•    POWER TO THE PLAYER!
•    Easy steps that MUST be done to not lose your game files
•    Your saved games typically are stored in the "My Documents" folder so they are not necessarily a part of this 'how-to'
•    This procedure only talks about the major core files that make the average Ubisoft Connect game run
•    In this example, I will only show the game Assassin's Creed Odyssey as it seems to be a very generic implementation that other games act identically and should work across all games using the Ubisoft Connect launcher
•    It is assumed your game is already installed but the drive it is on is running out of space. More DLC anyone?
•    The more DLC nonsense these game companies release WITHOUT allowing people to figure WHERE to store all these downloads without bursting their hard drives the worse gaming gets.
•    How lazy are developers to not even address these multi-Gig game folders in this day and age? What is this 1988?

1. Open the Ubisoft Connect launcher and go to your game (in this example 'Assassin's Creed Odyssey', your game can be something else, however)
2. Select Properties (located beneath the 'Play' button)
3. Look for 'Local files' section. You can NOT alter this and you NEED NOT alter this using Regedit anymore. There is a simpler way!
4. Click 'Open folder' the File Manager window will open and you need to up ONE folder so you can choose COPY (or CUT). Example: Default location is "C:/Program Files (x86)/Uplay/AssassinsCreedOdyssey"
5. Please note the developers of Ubisoft Connect do not understand the difference between a forward slash "/" and a backslash "\". The CORRECT way that should be used is a BACKSLASH "\", since these are novices they use the opposite and this has problems if you using a command line to move files. I am writing here what you should SEE in the box as THEY have it not how the rest of the world uses slashes. Once again when you do not know what you are doing you tend to screw everyone up. Ubisoft devs do not understand slash importance and use the incorrect form of slashes. Novices! They confuse the blackslash of INTERNET web browsers with the FORWARD slash of computers running PC software at HOME, not web servers! Really stupid mistake and clearly they do not understand CODING!
6. Move to its new folder location such as your large multi-terabyte drive (in this example drive "F:\"). You actually do want to MOVE or CUT it from the original location and PASTE it to the new location on Drive F: Move the entire folder from drive 'C:' to bigger drive 'F:' with either File Manager (comes with Windows) or a great free software like 'Terracopy' (just internet search for it) that does file copy VERIFICATION! (Yes, verification takes longer but it's still faster than downloading a corrupt file from the source server. You do NOT have to verify files but it is there in the event you want guaranteed identical copies/file moves. File Manager is rather devoid of any additional verification features even in the New Windows 11 File Manager ...shame =/
7. Once the entire folder is moved it will be moved from "C:/Program Files (x86)/Uplay/AssassinsCreedOdyssey/" to "F:/Games/Ubisoft/AssassinsCreedOdyssey/" ( it is assumed you manually created a folder named 'Games' and then a folder within that called 'Ubisoft')
8. Please note the direction the slashes are leaning is how the Ubisoft software sees it NOT how it is supposed to be written CORRECTLY! Please note there is a forward slash at the VERY END of the location too. The Connect software should show it to be identical as I have written it. Slashes and spaces and syntax and all.
9. Now you can click 'Uninstall' in the Connect software that will not even know you moved the files as you did it with File Manager or Terracopy it will quickly uninstall the software. It will do almost nothing and should finish in a few seconds. It will not remove your already moved games folder you just finished manually moving (Folder Cut and Paste)!
10. Now your 'Play' button should show 'Download' DO NOT PRESS DOWNLOAD!
11. Select 'Locate Game folder' beneath the button that says 'Download'. Point it to the F: drive (in this example)
12. The Connect software will find and automatically VERIFY the correct file size of the entire manifest for the game folder!
13. You do not need to 'Verify' the files implicitly as you would by selecting under Properties > Local files > Verify files as the previous step already did that!
14. You are done, now your game will be seen from the new drive and no copious downloading was needed! No actual uninstallation and Connect file deletion were performed either!

One day, whenever Ubisoft feels like making the movement of voluminous game folders as easy as STEAM has had it for YEARS then we can all know they know what they are doing. Until then, sorry, Charlie!