Expand blank page width with code - Jasper template

Hi, 

Im using Jasper template, most of my galleries (I have a photography portfolio website) are full page bleed. I wanted to create a blank layout page, unfortunately in this template Im limited to 1280px width. Don't know anything about code, is there a simple way to expand that to 1920px ? 

Thanks 

Hi, Please share link to that page, we can give code to increase width.