What are the steps to legalizing polygamy?

You would want to bring it before the Supreme Court. The court will sensibly not hear it the case. Not many people care. I certainly do not.

First you have define exactly what you mean by polygamy, and what legal changes you want made to specific statutes. Can any married person bring home a new spouse whenever they want? Does the spouse get full rights, or does the rest of the family have to formally approve it? Will businesses be forced to pay for medical insurance for multiple spouses and dozens of kids? How do you handle divorce, estates, custody rights, paternity responsibilities?

Then you have to convince the majority of the country that it is a good idea. You would start by building up a lot of data about how well it works, how happy it makes everyone, how it won't affect the economy or cost the taxpayers anything, how easy it would be to change over.

Of course, none of that is true, so this could be the hardest part. Gays worked for decades to convince us that they should be treated equally. They've shown repeatedly that they have no choice in their orientation, and can handle the responsibilities of marriage just as well as straights.

Polygamists have a long history here and abroad of holding their country back, feeding off welfare, abusing women and children. It's going to be quite a fight to change that image.

elect the Prophet to be president.

have the president make 4 supreme court appointments.

mission accomplished.

Gee, if only there was a Mormon in some kind of position of power or something. They like to have a lot of young girls as "wives".

None The thought of two - or more - wives is terrifying! :-)

There are none.