Over time, the condensation has dripped down between the glass and oven door.
There are 2 different ways to clean the drippings off.
Plus, the tutorial will show how to reassemble and reinstall the door back onto the oven.

Image by That Dad Mike via YouTube
Grab the sides of the oven and close it until its almost closed.
Lift it off and place it on a flat surface under a towel.
Remove the screws that are around the perimeter.

Continue to watchThat Dad Mike tutorialon YouTube for full instructions and details.
Once cleaned, reassemble and attach the door back onto the oven.
Sometimes it gets stuck between the glasses which causes to remove the whole entire oven door.

That method would take a lot of time so its easier to disassemble the oven door as a whole.
