It's not a boot drive, just a drive for computer gaming.
1. if its not a boot drive and its just a gaming drive you can just copy the data over via windows explorer after you connected both to PC. Do not worry about drive letter, as you will change all that once u finished copying the data over.
2. go into computer management -> disk management -> right click on the old drive -> "change drive letter" -> Remove.
3. on new drive -> right click -> "change drive letter" -> "add" -> assign the same letter as old drive up top.
Even if you cloned the drive as others stated above, you will still need to do 2 and 3, as windows will assign it a new drive letter, and your registry pointers will be all wrong, hence why 2 and 3 are important.
If the game is under a steam directory, you can do the method above, or you can just migrate the steam directory to the new drive, so you can use the 256gb as a secondary...
If you want to use the 256gb as a secondary you will need to assign it a new drive letter or it will not show up in windows explorer.
I'm hoping to install the 512, copy, remove the 256, rename the 512 to what was the 256 drive, and hope the system doesn't know the difference.
ahhh exactly.... make sure the new drive is the same letter as the old drive, and your good to go.
You just need to make sure the register pointers for the game match, or you will have issues.
Except make sure when you reassign drive letters both drives are in there, and you REMOVE the old drive letter though disk management.
Ive had cases where windows would not allow you to reassign a used drive letter without removing it.