Warning: this save also got some Achievement not related to the DLC Mad Moxxi's Underdome Riot,
if you want to enjoy getting other achievements, leave it for last.
1) Download https://drive.google.com/drive/folders/1neT2epP0-I_8ivZRaZA4fLxOI56twuXB save file
2) Create path C:\Users\user\Documents\My Games\Borderlands\SaveData if is not exist and copy save file (special thanks Invisible Man)
3) Run a Borderlands GOTY Enhanced Edition, in main menu click on Import Character and import they
4) Start game on this save and get achievement!
Save a few hours on very bored DLC