This will work 99% of the time for un-modded saves. If you want to transfer saves that have had mods, it is very possible but has a few more steps involved.

1. Start Skyrim (Launcher, without SKSE etc.).

2. In the mod section, just un-check any non-first party mods and the official texture packs(make sure you leave the official expansions checked).

3. Start the game and load your intended characters to make sure it does not crash. If it does, make sure you were not in a heavily modded area or wearing modded clothing.

4. (OPTIONAL) Create a new save. I do this to not to cause issues with my game in case I come back.

5. Exit Skyrim

6. Downlaod the Save Game Script Cleaner (by Hadoram) here:
http://www.nexusmods.com/skyrim/mods/52363/?

Then launch it and follow these instructions:

• Click open, choose a save game file.
  
• Click "Clean other", this cleans orphan array7 items + visited worldspace array items having a formId 0.
  
• Click "Clean formlists", this removes all form lists items with refId 0.
  
• Dont use "Inc.refs", unless you know what forms it deletes!
  
• Click "FixScriptInstances", it removes all orphan script instances.
  
• Click "Delete all #"
  
• Load a save in the game, and save it again. Now it should be fully cleaned.
  
• Auto backup, if on,(default) creates a backup from your save, named as backup-date-time.ess and backup-date-time.skse.

7. ONLY IF YOU HAVE THE OFFICIAL HI RES TEXTURE PACK ON YOUR ACCOUNT:
Highlight Skyrim in your game list and un-check the official hi res texture from the list of installed DLC so it removes it from your mod list and removes it from the game install.

8. Verify the integrity of the game cache
- this will re-download any default textures and items that may have been replaced by a mod and also replace any ini files that may have been changed. You can skip this step for time-sake but it is not recommended.

9. Start Skryim and double check to make sure the mods are not active (The Hi Res texture pack shouldn't even be there now).

10. Load into Skyrim and check the newest save to make sure there are no messages indicating that the save relies on any mods.

11. Copy your save files to the SE save directory
- from C:\Users\(username)\Documents\My Games\Skyrim\Saves
- to C:\Users\(username)\Documents\My Games\Skyrim Special Edition\Saves

12. Play and enjoy!


If you have any difficulty, please comment and I will try to help you.

1. Start Skyrim (Launcher, without SKSE etc.).

2. Check to make sure no mods are installed in the launcher.

3. ONLY IF YOU HAVE THE OFFICIAL HI RES TEXTURE PACK ON YOUR ACCOUNT:
Highlight Skyrim in your game list and un-check the official hi res texture from the list of installed DLC so it removes it from your mod list and removes it from the game install

4. Copy your save files to the SE save directory
- from C:\Users\(username)\Documents\My Games\Skyrim\Saves
- to C:\Users\(username)\Documents\My Games\Skyrim Special Edition\Saves

5. Play and enjoy!


If you have any difficulty, please comment and I will try to help you.