Photos photos photos.

Before you begin, take a series of photos of the playfield top to bottom on both sides as a reference in case you miss something later or need to see how something was originally assembled.

Take photos from different angles--above, below, and sides.

Take photos of where wires connect in case they snap off.

When you think you have enough photos, take a couple more just in case.

Every time you remove a screw or part, take a photo.

Be sure to back up your photos to a second device or location, especially every time you take a break. I usually copy them to a computer. So, if something happens to your phone/camera, you don't lose anything.