Q.How to kill wildflowers
My lawn is rock, rockscapes, and wildflowers. I want to kill the wildflowers and start over. One particular variety has pretty much taken over the entire lawn.

As with many things, when you look into it very deeply, getting rid of weeds has many ramifications. One way is to know what kind of weed you're looking at, and attack with specific measures tailored to that weed.
However, looking at general weed eradication, here are some articles highlighting different approaches:
https://www.gardeningknowhow.com/plant-problems/weeds/using-herbicide-in-gardens.htm
https://www.gardeningknowhow.com/plant-problems/weeds/what-is-flame-weeding-information-on-flame-weeding-in-gardens.htm
https://www.gardeningknowhow.com/special/organic/homemade-pet-friendly-weed-killer.htm