How to edit UberMenu's default background images

Hello there,

Curious where to edit the background images from UberMenu? They actually link to Skywarrior’s website and appears to be in-line.

If I go to the UberMenu panel and actually delete the image (which there is none there) it overwrites it and doesn’t appear there anymore

Please see this link: http://prntscr.com/g577i7 – THis is before removing anything
After just editing the ubermenu and trying to upload a new image… I get this
http://prntscr.com/g57e15

My menu is all broken, I believe due to hardcoded links/images… which is fine, provided you can let us know where to edit these.

What’s the best way to fix these? Thanks