There are a couple ways to do it, but it is slow going. While I love this game, it is a bit of a grind. There are some events that will lower shame, one of them is to do all three mage events. You lose 1 shame for each event. Also, if you can not pay the rent and clean 2 or three times, you will get a lowered shame when you clean in your underwear. There are others, like there is one with Freja, but they should show up in normal game play.
The other way to do it is to rescue the queen and get access to the commons. The church will provide you with reduced shame every time you make a donation. You can use the 3 red seeds to help with the frequency on this.
I will tell you, once I got the shame down to 84, I could not get it any lower, even though it said I was earning a reduction point so with max Shame and at night, you only get to 74% so you are going to have to use the cheat to lower it farther. The dev said that late night was supposed to trigger an additional 10% reduction but that there is an error and it is not firing and will get fixed in the next update.
EDIT. Sorry... just noticed there is a hot fix available to fix this on the first page.