The whole discussion is over a moot point. The Chinese government cannot be convinced to quit Tibet, nor can they be expelled by force. China's persistent claim to Taiwan demonstrates their resolve to pursue what they see as their rightful claims on territory. Further to that, China has already announced that it will go to war and use nukes if anybody including the U.S. interferes with it's plans in Taiwan.
You can think of it like the Cold War with the USSR, which took nearly 50 years to release the countries of Eastern Europe from Soviet control. China will not fall prey to the USSR's downfall, however. The Chinese leaders are not stupid and have learned from the USSR's bankruptcy. Rather than draining their economy by strict adherence to communist principles, China is growing wealthier and economically more powerful every day through international trade. Unlike the USSR, China is here to stay, growing stronger and more determined to pursue it's national interests. Tibet??? Feel bad, but forget about actually doing anything. Tibet will be free when China decides it will be free and there's not a damn thing anybody can do to influence that.