you buy an adapter to convert the hdmi to dvi. just be sure the dvi end is the right one since there are multiple versions of it.
it's that simple. you can get a cable with the 2 ends what you need or simply an adapter that converts right at the gpu.
they are not that expensive. a simple hdmi to dvi search on newegg or amazon will turn up plenty of options
That won't work; Please see section 4.5 here: https://forums.tomshardware.com/threads/how-to-connect-to-a-120-hz-display.3268285/#post-20043088