Install Instructions:
1. Download the save file and unzip it 
2. Download Elden Ring Save Copier
3. Locate your original (ER0000.sl2) save file here: C:\Users\your_name\AppData\Roaming\EldenRing\7656XXXXXXXXXXXX
4. Make two copies of your original (ER0000.sl2) save file: one on your desktop, and one on your google drive for safe keeping
5. Open the executable program named Elden Ring Save Copier that you downloaded
6. Click on the Browse button under the Source File option
7. Select the borrowed (ER0000.sl2) save file that you extracted earlier
8. Click on the Browse button under the Destination File option
9. Select the copy of your original (ER0000.sl2) save file that you made on your desktop
10. Now click the Copy button to finalize the conversion
11. The copy of your original (ER0000.sl2) save file will now be a registered copy of the borrowed (ER0000.sl2) save file
12. Go back to: C:\Users\your_name\AppData\Roaming\EldenRing\7656XXXXXXXXXXXX
13. Delete everything inside the folder (ER0000.sl2, ER0000.sl2.bak, and steam_autocloud.vdf)
14. Copy over your newly registered save file that used to be your original (ER0000.sl2) copy
15. Run the game via Steam like normal

I would recommend playing offline if you don't wanna risk getting banned.
Special thanks to CombatEng1neer for making the instructions.