You can change your password details in My Account section under Account Information.
G2000: https://www.g2000.com.sg/customer/account/edit/
Cath Kidston: https://www.cathkidston.com.sg/customer/account/edit/
LAMALOLLY: https://www.Lamalolly.com.sg/customer/account/edit/
wt+: https://www.wtplus.com.sg/forgot-password/