Below are the step by step guide screen shot to show you how to change technical contact detail for .MY (MYNIC).
Step 1: Log on to http://www.domainregistry.my
Step 2: Enter your Administration Contact Username and Password
Step 3: Enter your Administration Contact Username and Password
Step 4: Locate [Domain Name] then locate [Modify Domain]
Step 5: Enter Domain Name that you wished to change technical contact, then click [search] button at the bottom right corner.
Step6: Check the Domain Name that you require to change technical contact, and click [Modify].
Step7: Change the details and click modify.