Widget sidebar below slider?

Frontier is a great theme — heck, I even donated!

There’s something I’d like to do, but can’t: Put a slider above the main content and right sidebar. To put it another way, I’d like the sidebar below the slider. This is just for the home page, FWIW.

As it now stands, when I add a right sidebar, it cuts off the right end of the slider.

I’ve put pictures of what I’m talking about here:
https://www.chojnacki.us/frontier-sidebars/
The actual website is here:
https://chojnackiforassembly.com/

This may be so simple that I’ll figure it out before anyone replies,but I’ve been toying with it for a while with no luck.

Thanks for any help.

Greg