Yes, you can change your personal details by clicking on “Edit Profile”, answer the Security Question and proceed with your changes.
Things can be edited from in app edit profile:
2) Birth of date
3) Preferred channel of contact (Email/SMS)
Others info that can be change:
1) 6 Digit PIN - How can I change my 6-digit pin from my Touch ‘n Go eWallet account?
2) Mobile number - How can I update my mobile number on TNG eWallet?
3) Security Question - What do I need to do if I forget / want to change my Security Questions?