On the bottom of the negative carrier are 3 screws. Under the two screws on the right are springs.

Remove the two metal plate held by two screws each. Don't forget to replace with fresh lube when reassembling.

There are still two worm screws in the corner. they do not hold anything. They are just there. Probably better to remove them so they don't rust.

Clean both metal pieces with soapy water or appropriate solvents for stains and grease. Dry with towel.

Clean the glass squares with lens fluid and microfiber cloth.

After is everything cleaned and 100% dry, reassemble.