Not sure at this point if it can be done. But if you can help that would be awesome. Png is currently 48mb and it is the correct size for printing set as well as resolution at 300 dpi. i cannot make the size smaller or the reduce resolution, so is there a way to compress this file. I see lots of compression programs but none seem to be capable of handling such a large file. Thanks for any help.
PNG isn't a proper format for printing and generally does not contain any ppi flag. In addition, I don't believe PNG supports CMYK color.
If anything, a jpg may be more appropriate. If not tiff.
All those "compression programs" are designed for web images, because that's what the PNG format is for. They aren't geared for print images.
For print, file size (kb) is traditionally never anything to be concerned with. I mean that literally. When dealing with print images, you get the quality and color correct then save and don't even bother looking at file size. Concerning yourself with files size just means you will reduce the quality of the image.
Make certain the file is in CMYK mode and 300ppi. The save your image as a jpg with the quality set to 12. Don't use Save for Web or Export commands.. just Save As. Chances are the file size will be much smaller.
Ideally, you would save the file as a .tif and provide that a printer. However, there are some instances where providing high resolution jpgs are acceptable. I have yet to see any printer accept direct png files for reproduction.