It’s quite easy.
For Windows 7 or Windows 10, just plug in the USB cable into the phone.
It will say “USB Connected”.
There will be a button called “Mount” at the bottom of the interface.
Click “Mount” then press “Ok”.
After around 10 seconds, a window pop-up should appear on your computer’s screen.
Click on “open folder to view files”.
What you will see are the folders and files that are stored on the phone’s MicroSD Card.
After you have finished browsing the files, copy or whatever you had to do, just unplug the USB cable, no need to do anything else on the phone.