Looks like you are going to have to take out the two side units for the TV to fit. I think the wood is good looking and it matches the trim and details in your house, so I would spend money to have it modified to work with the new TV.

It looks like this piece could have been built in three or four pieces. I think you will need to remove the upper section with the doors, each of the speaker sections, as well as the center section. You should be left with the lower cabinet with doors. It's fairly simple, you could possible remove the cabinets yourselves. Undoubtedly, you will have to come up with a solution for a finished top. If you can't match the existing wood, find a slab of stone that goes well with the fireplace tiles.

I like the wood, agree it matches the other trim and flooring, and looks like good quality, so I would try to salvage what you can. Like the others, I would start by taking out the speakers and what looks like a low shelf between the speakers, and go from there.