You don't want to do this via the editor wjjz. That will take forever! I suggest opening your PCF file with a zip program such as WinRAR extracting the bitmaps folder and XML file. Next you'll want to replace all bitmaps in the extracted bitmaps folder with png files instead. Then add the entire contents of your extracted bitmaps folder (should be all png files at this point) back to your PCF file's bitmaps directory using WinRAR, choosing to overwrite all files when asked. Lastly, open the extracted copy of your XML file with Wordpad changing all ".bmp" entires with ".png" instead using the "Edit->Replace->Replace all ..." option, then adding that edited XML file back to your PCF file using WinRAR, again choosing to overwrite the original file. That's all there is to it. Hope you have not wasted too much time doing this in the editor. Working outside the editor as I've suggested here is the only way to go.