The only way to change your password is to make your account full...
This way you create the ID yourself. You can't change the ID once you make it. It is a permanent ID.
If you go to wasabii with a simple member account, go to the change password link, it forces you to create a full account. At this stage you are asked to place a nickname, another name, ID, D.O.B, 2 phones numbers and an address.
After you confirm whatever you place in the ID part of the form is your ID thereafter. The only people with any possible means of changing the ID is by talking to wasabii themselves and even then i am sure they would want a VALID reason as to why you wish to change it. As changing something like that can have serious issues with accounts.
Here is a way to prove my point: Create a simple account and try to change password...
Here is a throw away account of mine. Which i will post when you are online...
now go here
https://member.wasabii.com.tw/WA_mem...assword_a.aspx
This account is a simple account i just made. Now once you click that password change link it will ask you to make a full account before you can even think of changing your password. Once you have filled in the spaces and confirmed... well i explained the rest.