AZW3 Manga to KEPUB

I have made several attempts to convert a kindle manga to kepub for my Kobo Aura One with limited success.

The constant problem I keep running into after the kepub conversion are:

• Smaller image size (The panel should fill the entire screen).
• Header and Footer keeps showing up on each page.

So what I need is:

• Comic panel should fill up the entire screen.
• The removal of the header and footer.

I have attached screenshots of what Kindle and Kobo conversions.

I would appreciate any help to solve my issue.

Attached Thumbnails