Now that you have your Insight Statements (if not, check it here!), you know the problems you want to fix. The How might we? method consists on rephrasing them into questions that will help you find opportunities.
Using the "might" leaves the door open for any possibilities, it's much better than just the insight statement. The more "How might we?" you can create for each theme, the more doors it opens. The tricky part is to keep the questions broad enough but not too broad. (remember to not eliminate the possibility of wild answers now!)
Let's go back to the example I invented for the insight statements that was: "I like checking what I can visit or do on holidays because then I don't have regrets afterwards. But in the tourism office I would waste hours finding exactly what fits with my tastes and wallet without being sure if it's worth it. I wish I could find more personalized info with feedback."
A question could be: "How might we show the visitors that an activity fits with their interests?".