How do I remove no tarnish coating from sterling silver?

Hello this link might be helpful

https://www.bhg.com/homekeeping/house-cleaning/tips/how-to-clean-silver/

Use ketchup as a paste for cleaning off tarnish from silver.

You can also use toothpaste (non-gel) as a paste with a little water. Be careful to not use this on silver plated items, it will damage the finish.

are you wanting to remove the tarnish or the product you put on to keep it from tarnishing?

I sell a lot of silver on Ebay. Jewelry, silverware, serving sets. Silver polish like Wrights and dips like TarnX tend to remove some of the metal. The foil method doesn't work that great and still leaves a grey film that still needs to be removed. I use white toothpaste (not gel) and a damp toothbrush. For large items I use a damp cloth. Also works on copper, brass, gold, porcelain, ceramics, sneakers, plastics, etc. For my sales I needed one product for cleaning everything. A dab of toothpaste on a damp toothbrush and gently brush letting it foam up. Wipe off with a damp cloth.

If the anti tarnish coating is a form of lacquer then paint thinner or finger nail polish remover would be a good place to start but always do this on a spot that doesn't show to make sure you like the effect. Rinse well after using.

If you're trying to remove an anti-tarnish coating, I've heard ammonia and hot water will work. If you want to polish the silver, but some silver cleaner. It's available in most grocery stores.

I used BioCleaner, cleaning clay on some that were in my basement for years. Worked great.

You can use a cleaning paste. I like Bio Cleaner brand.