Hi @elmadele ,
Not sure if this is what you mean, but here’s is a [https://www.youtube.com/watch?v=YKY8qypnfuE|video] that shows how to open a Braun hand blender. It is in Spanish but the video is self explanatory.
I suggest that you use a small bladed (1/2” - 1” ) paint scraper or a thin butter knife rather than a screwdriver to minimize the cosmetic damage when opening the case.
Hopefully this is of some help