I am booked on the following route? Is it possible to slightly reschedule it ?

My present itinerary: New Delhi to Guangzhou (CZ360) leaving on 3rd September; Guangzhou to Changchun by CZ6342 on 4th
Changchun to Shenzhen on 7th by CZ 6488 ( I shall like to be in Shenzhen early in the dya on 7th)

Shenzhen to New Delhi by CZ3457+CZ3404+CZ359 ( Is it possible to take a flight from Hongkong and commute between Shenzhen and Hongkong on surface?)