Ok, good.

Once you open an elevated command prompt in Windows 10, ....

https://www.tenforums.com/tutorials/2790-elevated-command-prompt-open-windows-10-a.html

.... you would just need to...

That's ok. I'll be here when you're ready to continue. :)

Did you need any of the data on the drive that you can't access right now? If not, then it'll be easier to temporarily copy what you want...

Do you mean that the Change Drive Letter and Paths option is grayed out in step 6 of OPTION ONE below?

If so, then see if you may be able to use step 6 in OPTION THREE to do so in the command...

Hello Jimmer, and welcome to Ten Forums. :)

It looks like you may have had an OS installed on the external drive at one time?

Did you want to format the external drive, or just wanted to access...