If you use Windows 10 to create a recovery flash drive, at the end of the process you should be given the option to delete the partition (same thing is now on the flash). Then pull a system inage and you can use use the recovery flash to boot and the image to load the new drive. Only caveat: the new disk needs to be as large or larger than the image you pulled. (Replacing the 64GB with a 250 should not be an issue. Never say never).