currently my file system is dual boot between windows 7 and ubuntu 16.04. First I wanted to allocate space between the two operating systems, but now i decided it is best to just erase windows in favor of ubuntu. As far as I know, I have two options.
Boot into windows, boot from a brand new ubuntu usb stick, select "Replace xxx with ubuntu" (what stands in xxx? windows7/ubuntu?) The question is whether I have to deinstall the old ubuntu first or if the installer is capable of obliterating all partitions from the entire disk space and build a brand new system.
Remove windows 7 from the dual boot setup and allocate disk space to ubuntu. I would prefer that option as my ubuntu system and all the configurations would remain but am afraid of not being able to manage possible problems that might occur. Also it seems problematic that the free disk space would be left from my partition.
What is the easiest and safest way for someone who does not know anything about partitioning aside from pulling sliders in the windows menu?