Tong can in Kwun Tong first takes the subway to Kowloon Tong, then transfers to the East Rail to the University Station, and then the Chinese University comes out. After you have been to the Chinese University, you can take the East Rail to Hongkan, and you can see the Polytechnic University when you leave the station. After science and engineering students come out, take bus 103 or 973 at the roadside bus stop and get off at the east gate of HKU. After you get out of HKU, you can get off at Admiralty or Central and take any bus to Central, such as 3B, 40M, 23 and 40. You can get on the subway from these two places to Kwun Tong (you have to change at Mong Kok).

I think HKU's restaurant is cheap and delicious. It's on the top floor of Zhuang Yueming Entertainment Center Building. I recommend you to try it. The eating places around the university are not very expensive, and the general tea restaurants are similar. It's not much difference to look at one directly.

Octopus can't save much money, but it is very convenient. I suggest you buy one. Green minibuses can use Octopus.

Have a nice trip!