With a tub strainer dumbell wrench.
scrape it with a razor blade...assuming the tile is untextured porcelain
Yes, the whirpool duet tubs are made of porcelain.
Porcelain is a type of ceramic; it is not part of a steel tub. If the tub were made of porcelain it would not be made of steel. Enamel is a kind of tough paint that can be used on steel, or on porcelain.
softscrub
Possibly, if you really cleaned the tub aggressively with lacquer thinner or similar de-greaser.
it is a metal tub used for washing.
Once the old tub gets into the drain it is impossible to remove.........
A good basic cleaner is baking soda made into a paste. Scrub the stain with the paste then rinse. Spraying with vinegar before rinsing can help lift extra dirt from the surface. Do not use ammonia, it can damage the finish. [I found this out when I mixed ammonia and soap to remove a copper stain on a tub]
By disconnecting the tub shoe from the waste tee and removing tles around the tub
By un surrounding it
Pop them. Tediously. One. By. One.