When you complete a merge, you will be given the chance to choose which data to keep for fields where there are differences. For example, those two profiles have different death dates, so you'll have to choose which one is right.
Everything that's in the biography, sources, and pictures from both will all be safe in a merge.
Both copies of this person have parents and grandparents attached, so those will all have to be merged to. I recommend starting with the grandparents, then the parents, and finally Samuel. That's the easiest way.
Let me know if you need any further help with this!