Obtaining the permission and other stuff

Hi there,

I am writing as an exchange student currently studying at the Hangzhou Normal University (with an X2 Visa).

I would like to visit Tibet and the end of this month, but I am not sure how to get the necessary Travelling Permit, thus I am contacting you with a request for help. I am aware that I have to posses valid Chinese visa and passport and make scanned copies of these, but what is my next step after?

My plan is to get to Chengdu, stay a day or two there, then fly to Lhasa, spend 4-5 days in the city and in surrounding areas and then get back to Shanghai by plane.

Thanks in advance.

David G.