First of all: No offense, but this is one of the most serious penalties, it simply says that your site is pretty much pure crap. To get the penalty lifted, you need to file a reinclusion request. For a successful reinclusion, you need to fix the problem first, completely. Only deleting the content won't help, you need to present Google a site with content that actually has value for visitors. Just "unique" rewritten Amazon customer reviews to pretend you are a "review site" or similar won't cut it.
Be aware this means no less than rebuilding from scratch, you'll never get out of this penalty by just adding a few hundred words here and there. If you don't have loads of great links or a premium domain, think about starting a new site instead. Sounds harsh, but it requires the same effort onpage minus the reinclusion request.