You mean you want to cut it into smaller images?
Load the image.
Convert to a bitmap.
Encode arbitrary rectangles as PNG.
Save the PNGs.
Unfortunately, I don't know anything about image processing usinf J2ME libraries.
Here's what I googled as far as loading a PNG in J2ME.
Using that, you'll be able to see the API calls used, and following the import
list, you'll get to the classes used. Look at those class's methods, and yu'll probably come up with what you need.
I did this mostly because you're having an emergency, but frankly, you could have googled this yourself, or composed a question that was clearer, which would have led to someone more knowledgeable about J2ME image processing helping you.
Just don't panic, take a breath, google for what you need, you'll be fine.