How to remove headers with images in pdf?

[Princess kindle]

Hi everyone, I have 2 questions and I don't know if I should ask them all in different posts.
1. I have several books in pdf that have headings with images, how can I remove them? When I edit the book manually if I delete the image, a symbol and space remain. There must be a smarter way to do it.
2. Some books in mobi or epub have separate lines, that is to say, it has a line and then a half and then 1 and so on. Is there any way to fix it? because if I go to modify the book I have to fix line by line.