1. Download Source 2 Viewer: https://valveresourceformat.github.io/
2. Drag \game\csgo\pak01_dir.vpk into the Source 2 Viewer
3. Extract a correct localization into an empty folder keeping the same hierarchy
   My game language is English, so I extract resource/csgo_english.txt into an empty folder
   
   The final path should look like: <empty folder>/resource/csgo_english.txt
   
4. Open extracted csgo_english.txt, find SFUI_bot_decorated_name lines and remove BOT prefix like this:
   
   Save changes!
5. Pack the empty folder into .vpk using Source 2 Viewer
   
   
   
   When saving as .vpk, give it any name (i will name it hide_bot_prefix.vpk)
   
   
6. Create overrides folder in the \game\csgo directory and move hide_bot_prefix.vpk inside
   
7. Edit \game\csgo\gameinfo.gi and add the Game csgo/overrides/hide_bot_prefix.vpk line like so:
   
   Save changes!

Each time you verify or update the game, it resets csgo_english.txt and gameinfo.gi files
If you want to hide the BOT prefix again, just repeat the tutorial from the beginning