Frigidaire Dishwasher

How do I replace the top rack. I already replaced the bottom rack, but the top rack has an arm in the middle and I don’t want to just pull it because I don’t want to break it off. How do I get the arm off of it to take out the old rack?
Thank you.
Jim

Can you supply your model number. It should just clip on the rack, but with a model number I can look it up. Thanks.