CLR should do the trick!
I clean with Scrubbing bubbles, first. Microfiber cloths, and magic erasers will help.
Baking soda and Dish soap or WD-40 should do it.
Soft scrub and a scrubby works great.
Try a descaler like this: https://maurawhite.norwex.biz/en_US/customer/shop/product-detail/466362?categoryName=Bath
And follow up with this invisible shield to avoid future buildup: https://amzn.to/2JGuULl