Changing the number of images in slider

Hi there.

I’m trying to add 8th image into the slider, but got no luck yet. Ive read the FAQ, but it’s been 5 years since the last person wrote how did he/she add image. I know that i have to add <li class="bk7"> because it starts from 0 to 6, but where?

Header.php, line 307 – didn’t bring any changes.

thank you in advance.