You dont need to correct your initial profile page where you made mistake. Put correct information in continue application page and write a letter of explanation where you should mention it was a mistake. Once you finish filling up all details in application, you will be redirected to document upload page. There you will upload your work reference letter and also LOE for this in "client information" placeholder. This change of information regarding designation does not affect your crs score so it will not create any problem at all.
