I suppose the OP has already moved on, but I'd like to add something for future reference.
First, I'd suggest not to use a text editor to make changes in binary data. A simple hex editor (e.g. 
HxD) is more suitable for that. Also, last time I checked, that tutorial was missing some key information without which you are likely to corrupt the save file.
Both 
Paranoia and 
Force User are passive feats, which means they are 
only stored in a list contiguous to the skills list. Since this is a simple respec, swaping one for the other can be done relatively safely in a few steps:
1. Using the file explorer, go to "
C:\Users\<YourUserName>\Documents\My Games\Underrail\Saves\<YourSaveFileName>\".
2. Create a backup of 
global.dat and store it somewhere 
outside the save folder.
3. Using 
7zip, extract the contents of 
global.dat (the resulting archive should be named 
global, but that can change if you have renamed 
global.dat to something else).
4. Open the extracted archive (
global) using 
HxD5. In HxD, press 
Ctrl+F and search for "
paranoia".
The result, two columns with hexadecimal code on the left and its ANSI translation on the right, should look something like this:

As you can see, the name of the feat (right column, text highlighted in blue) is encoded as a series of octets (left column, hexadecimal code highlighted in blue). The missing information from the tutorial above is the string-length (left column, octet surrounded by a red square), which corresponds to the hexadecimal length of the feat name. This is a very common way of storing strings, so if you want to change the feat, at the 
very least this octet needs to be updated accordingly.
6. In the left column, swap-out the name of the feat encoded in hexadecimal code (in this case 
paranoia), for the name of the feat you want to swap-in (in this case 
forceuser). Since the name lengths do not match (
paranoia < 
forceuser), you also need to update the string-length from 
08 to 
09.
The result in HxD should look something like this:
7. Save the modified (decompressed) 
global archive you just edited.
Now comes the unsafe part, and the reason why you made a backup of 
global.dat. 
8. Using 
7zip, open the original 
global.dat (Right-click -> 7zip -> Open Archive).
9. A 7zip window will open, where you should see a 
unmodified global archive inside. Drag your 
modified global archive to the 7zip window. This will overwrite the existing data with your modified one. It will ask if you are sure, accept.
10. In-game, reload the save you have just modified. Note that you should not need to restart the game at all.
The new feat should have replaced your old one. If the save cannot be loaded (i.e. it is corrupted), please leave a message here, I'd like to take a look.
Before you get any ideas, no, you cannot add feats in using this method.
The save file spec has been briefly discussed multiple times before: 
Oct 22 2016, 
May 6 2017, 
Jan 19 2020, 
Dec 13 2019. While it is true that there is a certain degree of obfuscation, I believe this is just a matter of having a public project dedicated to reverse engineering game files. It doesn't seem like any of us have much time or interest to do it, but if someone wants to start figuring things out I'd be happy to contribute code.