Simple STEP File Creation

I need a STEP file created for a lab jar stopper. The design is quite simple, featuring a tapered hole and a slit along its length.

Requirements:
- Exact replica of provided measurements from attached images.
- Created using SolidWorks.
- Deliverables:
- STEP file
- PDF with dimension annotations and material specifications

Ideal Skills & Experience:
- Proficiency in SolidWorks
- Experience with creating precise STEP files
- Attention to detail to ensure exact measurements are followed