ChumSearch malware/How to get rid of it?

So I accidentally downloaded or somehow ended up with something called ChumSearch, and it's my new default search engine/browser, and i tried just switching it and uninstalling the safari extension, but even after I uninstalled it it's still there. I followed the instructions on this post but they didn't work. Any help would be greatly appreciated (the quickest the better, my parents will kill me if i do anything to my laptop). Thank you!