Hi, If possible, if you have good score and can wait till next drawn, best thing is to decline ITA and update the profile so that you wont be in dilemma. But, if you want to proceed, then advise is to make strong LOE and submit it.
You can change NOC with LOE as long as it is not too much different than what you have reported. Does not impact on your score as long as it is NOC 0, A or B. But, make sure you write a good LOE