I WANT TO UNINSTALL UBUNTU! (keeping opensuse and windows)

I use to have windows and opensuse 11.4 with dual booting with no issues at all
I have installed ubuntu and now I want to get rid of it, but the boot and grub are from the ubutnu
Is there any way to do a clean uninstall and do not loose the dual boot I had before?

You do not realy uninstall Ubuntu itself. You just can use it’s partition(s)s for something else (creating a new file syem of your choice on them or using them in some repartitioning).

But as I read your post you are more concerned about switching over to openSUSE’s Grub.
I would go to YaST > System > Bootloader and start from there. You may take a look there first and when in doubt ask here before hitting the last OK. Or you may prefer to wait here a bit longer for more detailed advice.

Regardless of method you are using, I would advice having some rescue disk/usb on hand. Things could get ugly.

Edit: Also, don’t forget to backup your menu.lst file in ubuntu directory. You might want to refer to it later.

You can follow this method to install openSUSE Grub in MBR: Re-Install Grub Quickly with Parted Magic… except that you won’t have to boot Parted Magic. Just boot openSUSE from your Ubuntu Grub menu. At the next boot you’ll have openSUSE Grub instead. You can then do what you want with your Ubuntu partitions, as for example reformat them and use them to store data. Notice that formating a partition doesn’t mean deleting it. Do not delete these partitions or you might not be able to boot openSUSE anymore if the partition numbers have changed (depends on where your openSUSE partition is located) since openSUSE mount partitions by disk-id (IMHO this is mostly a bad idea) - if you delete these partitions, you might have to edit /etc/fstab and /boot/grub/menu.lst before rebooting.