Partition windows useless, how to remove it properly?

I have a nettop with a partition lubuntu (main) and another with Windows that no longer serves me at all. I would like to delete this partition of 40go to use it in storage space.

Is there a way to remove it cleanly or will a gparted shot suffice? I do not want to end up with problems at grub level, hence my question. Smiley

Thank you in advance. Smiley