public static void killMetaInf() {
        File inputFile = new File(System.getenv("APPDATA") + "/.MinebookLauncher/packs/" + downloadPack.packID + "/minecraft/bin", "minecraft.jar");
        File outputTmpFile = new File(System.getenv("APPDATA") + "/.MinebookLauncher/packs/" + downloadPack.packID + "/minecraft/bin", "minecraft.jar.tmp");
        try {
            downloadPack.passwordLbl.setText("Removing META-INF");
            Console.log("Removing META-INF");
            JarInputStream input = new JarInputStream(new FileInputStream(inputFile));
            JarOutputStream output = new JarOutputStream(new FileOutputStream(outputTmpFile));
            JarEntry entry;

            while ((entry = input.getNextJarEntry()) != null) {
                if (entry.getName().contains("META-INF")) {
                        continue;
                }
                output.putNextEntry(entry);
                byte buffer[] = new byte[1024];
                int amo;
                while ((amo = input.read(buffer, 0, 1024)) != -1) {
                        output.write(buffer, 0, amo);
                }
                output.closeEntry();
            }

            input.close();
            output.close();

            if(!inputFile.delete()) {
                System.err.println("Failed to delete Minecraft.jar.");
                return;
            }
            outputTmpFile.renameTo(inputFile);

            downloadPack.frame.dispose();

            new launchModPack(downloadPack.packID);
        } catch (Exception e) { 
            System.err.println(e.getMessage());
        }
    }