Right-click the database you want to move to another drive and click Properties
In the Database Properties window, select Files and scroll over to find the file path for the Database and log files:
Make note of this path as you will need to Copy the files from here to move them to the other drive.
Close the Database Properties window. Right-click the Database > Tasks > Detach…
Click OK to Detach the database. This will allow you to move the database files and will be the start of downtime for the database.
Once the database is detached, go to the path you found earlier and copy the DB.mdf and DB.ldf files.
Navigate to the location you want the files and Paste them there.
Back in SQL Server Management Studio, Right-click on Databases > Attach…
Click Add…
Navigate to the new location of the DB.mdf file, select it, and Click OK.
Click OK in the Attach Databases window.
That's it, the Database is now attached from the new location. You should be able to delete the database files from the old directory if desired now provided the database functions as expected from the new location (which it should, Copying vs. Cutting earlier in the How-To was mostly just a precaution).
