This is a very good BIOS simulator page with various BIOS simulators for various Lenovo products.
There are Laptops and Desktops in this list. Just hover over the pale square in the top left to access the menu.
You could follow along with the person seeking help and be on the same screen they are on and tell them exactly what to do.
Below is a screen-shot of the simulator in action. The pale square in the top left is the menu to select a different Lenovo PC model and view the BIOS screen.