First of all, you need to install usb drivers, in order to connect your phone with Your PC. Use "Setool2lite" to find the EROM CID of your phone, by pressing "IDENTIFY" button. Then save your GDFS(it's very important), by pressing "READ GDFS". I suggest you to update your firmware to R4EA031(it's not the latest but there are many patches), by flashing MAIN, FS and Custom file according to your CID. After that you can apply the patch "remove_java_security_restrictions.vkp".