3D STEP File Custom Split Needed

I require a very small edit on a 3D step file. The project involves splitting a 3D object into two separate parts. This split isn't a standard cut; it's a custom split which necessitates some precision and care. After the split, there's no need for any specific details or features on the separate parts. Just a clean division will suffice.

Ideal skills and experience for the job:
- Proficiency in 3D modeling software
- Experience with STEP files
- Attention to detail
- Ability to follow specific instructions