Onshape Surface Model Rebuild

I have an existing STEP file that I now need rebuilt directly in Onshape as a set of clean, fully editable surfaces. The goal is to reproduce the geometry so accurately that it overlays the original STEP with virtually no deviation, yet remains parametric enough for future tweaks... (Budget: ₹4000 - ₹6000 INR, Jobs: 3D CAD, 3D Design, 3D Modelling, CAD/CAM, Mechanical Engineering, Product Design)