Preserve Ubuntu/Win7 dual boot after moving/resizing current Ubuntu partition

I have Win 7 and Ubuntu 15.10 dual booting at the moment.

Win XP on sda1 is what I am trying to get rid of, so that I can then expand sda2 LEFT and resize sda6 (Ubuntu) LEFT to give me more room.

As I understand it, grub2 is now installed on sda6 (?) and if I make the changes I describe above using a LiveCD, I will be losing my current grub2. Is that right? And if so, how do I go about restoring Grub2 so that both the Ubuntu and Win 7 installations are detected?

Thanks for your help!

Current GParted screenshot