Is there no way to expunge units from your record?

I contacted my major advisor. He said 70 units max goes towards my degree. I guess this means that the other units still do count against me?

Also, he stated after the 140 unit max, I’ll be given an extra 10 units (a 150 unit max), where I can only take classes towards my major. Then after that 150, I may lose financial aid.

Perhaps, I’ll wait until my last year to test my luck? When I have a better idea of how many units are actually on my record.
I can’t imagine screwing up and not earning my degree because of one or two extra classes I took up. But I just wanted all the information so that I could make an informed decision about which classes I do (or don’t) take.