Doesn't look like too many takers on this question. If I were you I'd use Win32 Disk Imager to create an image from the 512GB card, then use that image to transfer onto the 1TB card. That leaves the the Android partition (ext4 partition) unchanged in the new card; so if you want to extend that partition, you can use another free tool like MiniTool Partition Wizard to resize that partition to utilize the 1GB space. The down side to that process is that you'll have to have enough space on your PC to hold a 512GB image. If you don't have that space on your PC, my other option would be to use a Linux computer of some kind to transfer the image from the 512GB to the 1TB directly using the dd command (just google how to duplicate a sd card using the linux dd command); and after that resize the Android partition. If you don't have a Linux computer, you can do a USB-bootable Knoppix flash drive to temporarily boot one up. In fact, if you have Knoppix working, look into "gparted", which is part of that Knoppix distribution, it can help in duplicating that sd card.
I know it's not a guide, but you have some leads there to look into.
