Why can't you afford spending a month on this subject? It helps you in so many other subjects as well. 10 days is not doing justice to the subject as well as yourself.

If you really want to finish it in 10 days, I will suggest go through Goldstein's book in 10 days. That is definitely doable. Then you can spend time on the past papers.

I wouldn't recommend the approach suggested by Umer Haider. IR is a very important subject. You can use the suggested approach in smaller subjects like US History, SOciology etc but I doubt it will work for IR.