Epson Apex 20020 - Manual (Page 66)

To remove a 3½-inch diskette, press the release button to
release it. When the edge pops out of the drive, pull out the
diskette and store it properly.
WARNING
Never remove a diskette or turn off the computer while the
drive indicator light is on. You could lose data. Also, be sure
to remove all diskettes before you turn off the computer.
Write-protecting Diskettes
You can write-protect a diskette to prevent its data from being
altered. When a diskette is write-protected, you can read it and
copy data from it, but you cannot store new data on the
diskette or delete any files it contains. If you try to change data
stored on a write-protected diskette, MS-DOS displays an error
message.
To write-protect a 5¼-inch diskette, cover the small,
rectangular notch (shown below) with an adhesive write-
protect tab. Write-protect tabs usually come with new 5¼-inch
diskettes when you buy them.
To remove the write protection, peel off the write-protect tab.