My Son (8), God love him, was amazed at how much metal is in the interior of an old car in the process of investigation he put his fingers thru one seem in the headliner. What do I do???? I am assuming I would have to take it completely out and sew it back together from the other side. This is a daily driver that I am fixing up as I go. Is there a "quick fix so I could live with it until I get to that point in the restoration. Or Is this an easy thing to do? It is the first seem from the rear. I attached a photo.

Im thinking a good upholstery shop could fix it with a needle shaped like a fish hook? with out even having to remove it.

I had a similar issue with my headliner. It seperated on one seam and I was in the same boat as you. I drive my car regularly and will be doing a resto sometime in the future, just not ready to tackle the interior yet. I used zip ties and cut a small slit on the two lips of the headliner and zip tied them to the metal support rod. This will probably require me to get a new headliner when the time comes, but for now, it holds my headliner up well and prevents it from splitting further.

do it yourself with a sewing kit. cant be that hard. right?

Not sure what your future plans for the car are, but if you have a pristine original headliner that you want to save, I'd consider doing nothing right now. If it tore in the seam, it's probably just rotten thread. If you repair it in place, you will put needle perforations in the liner that will be permanent. If you want to save it when you restore, you can remove it and have a shop resew the seams.