What steps do I need to take to move my SQL instance to a different drive on the same server but with the same drive letter? I need to move my SQL instance to a different drive on the same server but plan to rename the drive to the same drive letter as the original drive the instance was on (after renaming the old drive).

I'm guess I need to stop the SQL service before moving the files, and then start it again.

Are there any other steps needed or precautions I should take?

Note: This instance has databases that are part of synchronous AlwaysOn AGs. Some of the databases are the primary replicas while others are secondary replicas. The primary replica databases are also being moved from the same source and to the same destination drive (as the server instance files).
There are the usual precautions such as ensuring up to the minute backups before you start.

Another option you could consider though is to create Mount Points for the new drive so that you don't need to worry about changing drive letters afterwards - the fewer moving parts the better.