Wallpapers to I file from camera roll

[spg0910]

How do I get a picture on my camera roll to I file? Changing wallpapers on themes sometimes requires renaming them xxxx.png but I am new to theming with I Phone. I also do not know how to use computer to do stuff like that, I rely totally on ifile. I downloaded I folders to laptop but do not know much about and I know messing with these files can really screw things up so I guess my question is kind of broad. But I see the people on here are not only very good at this stuff but very willing to help....

Thanks

[smi4450]

Any pictures in your camera roll can be found in /var/mobile/Media/DCIM/100APPLE
It can sometimes be 101 / 102 / 103APPLE etc depending on how many pictures you've had