User blog comment:MHS0501/How to change neighborhood picture in Sims 2/@comment-24258073-20150730061643

My Documents / EA Games / The Sims 2 / Neighborhoods / N001 / N001 Neighborhood.

Then open it using a picture editing program, such as Paint, or Photoshop, copy the image you want it replaced with, and then paste it over the top of the original.

I did it using Paint.