Hack the Remington PG6150 beard trimmer replacing the batteries

The batteries of the beard trimmer, after 4 years of career, no longer had the same duration. The autonomy had gone from 60 to 30 minutes. I decided to give it a new life by simply replacing the batteries. I believe it will be able to work another 4 years. Used material: If after watching the video you feel like getting a new one, I suggest these ... :)