@NassFas, I appreciate the attempt to move the collar but it could be much improved upon. You don't need to nudge it so high up, and the join between the collar and the neck needs to be much smoother; on the left it looks like the collar goes into his skin and on the right there's a gap between the neck and the collar. You need to move them separately, and to check (pixel-by-pixel) if need be, that the join is indeed natural.

Have a look at the text and video tutorials for this technique in the tutorials thread for some help on how best to do so 👍