Is there a way to keep/replace a sim's diploma in a new save?

@Starfree Thanks for replying! I do want to change one of my sims traits and his relationships, but I also thought starting a new save might be useful since my current save is quite old now and there have been a lot of bug fixes recently. I am not having many issues though so I suppose I could simply use MCCC as you suggested. I have now managed to recover an older version of my sim at university, so I also could go back and redo his last term. I will lose some progress which is annoying, but oh well. :)