What's the challenge exactly? Looks like nothing troublesome to model. Make a profile and extrude or combine a few primitives or sculpt from a sphere . There could be gazillion ways.
Make a box, convert to poly, make some cuts, push vertices to closer represent final form. Repeat cuts and moves until you satisfied with how it looks. Sculpt over it for fine detail. Bake to lowpoly.
yeah looking at the lowpoly, how straight the lines appear. i assume they built the lowpoly first, then used it to create the highpoly, not sure if it was actually sculpted or maybe just smoothed, baked and all surface detail is just done in a software like substance painter.