Like the background used in levels or the background for the world map?

I'm guessing the world map so

"ROM File Browser" > root > map > w1.nsbmd and the textures should be somewhere in there, though I suggest using a different program to edit it since NSMBe isn't that good at editing model textures

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"I strikingly thought you would know how but it clearly seems you have no knowledge of hacking" - MiiU 2017

Have hidden folders turned on (This will save you time with other problems down the road as well.)

Then navigate to C:/Users/(Username)/AppData/Local and then proceed to delete the folder "NSMBe4"


This does the trick for me
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"I strikingly thought you would know how but it clearly seems you have no knowledge of hacking" - MiiU 2017