because we have a representative why I cannot change it, if I have soft copies of it, can I change it and validate it myself or do i need to create a myicc account to fill up forms
You can fill out forms with
out myCIC account. I don't know how your arrangement with your representative is, but
anyone can fill out the forms as long as you have a software compatible with .pdf
My husband and I have a lawyer as our representative, and our arrangement was that we filled out all the forms ourselves, validated them all ourselves, printed and signed them all and then gave them to the lawyer. (She had to sign on the Use of Representative form of course, but none of the others.) She organized them and sent them to IRCC for processing.
Also as stated by the user above, you should make sure all the information is accurate even if you do not fill out the forms. "Misrepresentation" is when inaccurate information is submitted to the government, whether directly by you or done on your behalf. Even if you did not fill out the forms, if you sign off on it, you are saying you approve it, and you will be the one to face the consequences if there are any. Innocent mistakes or misunderstandings can be explained certainly, but it can be a pain. Easier to avoid it in the first place.
Looks like you found the answer to your own question. Then it is up to you whether you want to update your forms or not. But regardless, make sure you've fully checked all the forms over and made sure they are accurate. Despite having a representative, that responsibility does still fall on you.