Old Nintendo Minecraft world

I used to play on a server with a couple of friends like a year ago. I got the map of that servers, but somehow appear to be to stupid to upload it via FTB into the new server.

I’ve actually spawned in the world I had deleted in order to upload the old one, not sure how is that even possible, but ok. Also the map is only like 400 mb big while ours is around 1.5 gig in size.

Do I have to like go through FTB and if so, which program would you recommend? WinSCP seems to be very slow and not working properly.