My ticket code is EFZNWX, I need to change leaving time from 6 May to 13 May.

My air ticket no is EFZNWX. the schedule is take off from Shenyang by MU3210 from 6 May 2014 to Beijing.
And then on 7 May 2014 take MU0727 from Beijing to Nanjing, and take the same air plan from Nanjing to Sydney.

Due to my situation, I want to change the leaving date from 6 May to 13 may 2014. Could you please tell me which way I can change it asap.

Regards

Tianjian HU