Noted and thanks.
I just followed the steps and everything seemed fine. But after I Refiled it. It's rejected and it showed following message " The CRA cannot process this ReFILE due to system constrains. If the entries are correct, please send a paper T1 Adjustment form and attach all pertinent slips and receipts".
I'm wondering if it's due to the current strike of CRA staffs. Your inputs are much appreciated.