What law would I abolish? Shouldn’t be too hard to guess…
I would abolish, repeal and otherwise dispose of the odious, hateful and discriminatory California Proposition 8.
Thankfully, that process is well underway now, though not proceeding as quickly as one would like. I find the most interesting aspect of the court battle to be that the legally-defined defendants, the Attorney General and Governor of California, have declined to defend the law, and the "intervenors" (groups which wrote, promoted and are now third-party defenders) may not be able to demonstrate standing to appeal Judge Walker's ruling that the law is by nature a gross violation of the United States Constitution.
So the people who could defend it aren't, and the people who are defending it don't have any (legal, rational, secular) reason for doing so. Sounds like an easy dismissal to me, and the 9th doesn't even have to rule on the merits.

