How to edit obj file

I don't know how the heck do you
Edit obj file I try using blender but it doesn't
Work
Please help

I'm trying to make a mod

you can with blender,open blender then go to File then Import and then choose Wavefront (.obj)

This sounds like a question better suited for Google. Questions that you post here should normally pertain to Simpsons: Hit and Run in some way. Don't worry about it much; just keep this in mind.

This website may help you: wiki.blender.org/.