Uninstall Kubuntu from a dual-boot with Ubuntu?

I have a multi-boot system with Windows 7, Ubuntu 15.04, and Kubuntu 15.04 installed in that order. At the moment, I think my system boots through Kubuntu's GRUB. My Windows is installed on an NTFS partition (sda2); and all within an extended partition sda2: I have my Kubuntu ext4 (sda7), Ubuntu ext4 (sda6), and swap (sda5) partitions.

How can I properly uninstall Kubuntu leaving behind Windows and Ubuntu?

I don't think I can simply delete my Kubuntu partition using GParted from Ubuntu and run sudo update-grub can I?

Solution 1:

Try this:

Boot the computer from Ubuntu.

Open a terminal,

Press Ctrl+Alt+T

Run it:

sudo apt-get update
sudo apt-get install grub-pc grub-pc-bin grub-common grub2-common
sudo grub-mkconfig -o /boot/grub/grub.cfg
sudo grub-install --recheck /dev/sda
sudo gparted

Delete the partition using GParted, close it and continue running:

sudo update-grub
sudo reboot