Xubuntu persistence mode and rebranding instructions

Hi, I have a respin of xubuntu 18.10 what I need is to know (full instructions – step by step): 1- How to make my produced iso to enable persistence mode on it I check the iso with Linux live usb creator if I check Xubuntu or Mint they all have persistence mode enabled but my respined version of Xubuntu loses the feature? 2- How to customize the login screen which says try xubuntu or install xubuntu? I know it can be done I saw it customized on elementry OS so I need the full steps on how to changes the OS names everywhere to rebrand it Please don't give me instructions to unpack iso and work with chroot its impossible with my situation because I have so many gui changes so I need to work on installed Xubuntu on hard drive then respin it with pinguy. I just need instructions if your instructions will work I will hire u for future tasks :)