Most importantly, which way does it face? If it catches a lot of sun, I'm already thinking about climbing beans, tomatoes, cucmbers, a fig tree, grape vines - maybe even peaches or nectarines.
If it's noth facing you may struggle.
Containers or grow bags may get you started, and let you clear out small bits at a time over a few years. Once you've cleared out the top foot, I'd just let the roots do the rest.