Sim Data Not Importing/No XML showing?

It's possible that in your re-naming process something is accidentally being corrupted, or it could be an over protective anti-virus yeeting the info. Skip Step 3 as I don't recommend renaming files that way, continue to Step 4 and on to Step 5. Once everything is imported, follow this tutorial for renaming the XML files (you can of course skip the Create Empty Package and Extract Tuning steps since you already have your files).
If the data is missing after importing on Step 5 though, then maybe it is the anti-virus, so in that case I would recommend telling it to ignore the folder you're putting the files in.