Tutorial: How to Remove SVE Mid-Game
Removing SVE from an existing game is riskier than removing other mods and it requires more steps, but it is possible. Here's how to do it:
1: Create a backup of your save file and your Mods folder - that way if anything goes wrong, all you have to do is restore things to how they were. See this page on the Stardew Valley wiki to find where your saves are located.
2: Launch your save game and remove ALL items related to SVE from your chests/fridge, etc., including fish, forage, crops, wines and other artisan goods. If you skip this step, you will be unable to access that chest/fridge once you start the game without SVE.
3: If you are married to an SVE spouse (including the Wizard), you will need to divorce them. Use CJB Cheats Menu to give yourself the money if needed. See the Marriage page of the Stardew Valley wiki if you're not sure how to divorce your spouse.
4: Sleep to save these changes.
5: Install Reset Terrain Features (the original is outdated, so install either the unofficial update or the forked version). Once SVE is removed, it's likely that you will have bushes and trees in misplaced areas, so use Reset Terrain Features to remove them.
6: Remove SVE from your Mods folder, making sure you've removed all of its component folders. If you have any mods that rely on SVE, such as SVE portrait mods, you should also remove those at the same time.
7: Launch your game. SMAPI will give you a lot of warnings in yellow such as "Removed invalid villager [InsertName]", but these can be safely ignored. The warnings are created by SMAPI removing the leftover references so that your game doesn't crash. If you don't receive these warnings and instead get red text related to removed villagers, this means that SMAPI's Error Handler mod (which is automatically installed by SMAPI and should already be in your Mods folder) has been removed, so you'll need to reinstall SMAPI to get it back.
8: Check outside areas for any misplaced trees and bushes, using Reset Terrain Features if you find any. Once this is done, sleep again to save these new changes.
9: Extra optional step: install NoClip Mode to reach any forage that is now in an inaccessible location.
10: Extra optional step: if you are also using one of the two SVE farm maps (Grandpa's Farm or Immersive Farm 2 Remastered), use LenneDalben's Tutorial: Changing Farm Maps Midsave to safely remove your farm map.
Important Note: Sometimes Marlon may disappear, since SVE removes him in order to replace him with its own version. If this happens, install Make Marlon Real to fix it and bring him back.
Remember, if anything goes wrong, you can always restore your backup save and Mods folder!