Mojibake characters cleaning

I would like to know the process to clean the text data in the file, I have tried different approach such as changing the file encoding to UTF-8, using online encoding, using cleaning commands, VB and python script but am not able to properly clean all data. I have check online for different approach and applied them but to no avail. I have checked using a online website for Mojibake decoder which helped but required manually decoding each text, which is not feasible. Sp please help with this.