Similar difficulty for either.the easier / faster one
Both include going inside the case and physically disconnecting things.
Clone:
Disconnect ALL drives except the current C drive, and the new NVMe.
Follow the steps above, to include disconnecting the old C drive at the end of the process.
Clean install:
Disconnect ALL drives except the new NVMe.
Boot from a USB that you created with the MediaCreation tool from MS.
Install on the new drive.
The easiest thing to do is one of 2 things:
1. Leave the OS where it is.
2. Find a local computer shop, and have them do this.