Migrate from 2TB MBR single (user) partition to GPT >2TB Boot drive

This seems like it should be easy and straightforward; it's not. I am using an old-fashioned NTFS partitioned hard drive in a single partition configuration. I purchased a 6TB hard drive and wish to migrate my OS and all the data on the drive to the new drive and convert it to GPT and of course make it bootable. There is one hidden partition with the OS files on it but obviously no ESP. What is the simplest way to migrate this? What are the current best practices?