Hello there!
This one gave me a headache. The vertex remesh approach in sculpt mode shown by Grant resulted in a lot of artefacts, to the point the mesh became useless.
Instead, I applied the multires modifier at level 1 (after applying to base mesh), then used decimate modifier, followed by the shrink-wrap.
The face count dropped from 8,555,383 down to 8,148 faces
Will clean up a few vertices, like the horns.
Looking forward to seeing if the shoulder scales will work in UV unwrapping - or if I’ll die trying. 
Cheers,
Ray
ps: MultiRes worked, since I used this modifier to sculpt the dude. Might become my go-to approach.