Some PSI question, apologies if these are basic questions that are blindingly obvious. I couldn't find any docs after a cursory search:
1) Given a PsiClass that extends Class X, how do I make it not extend said class? I want something like psiClass.setSuper(null)
2) What's the best way to iterate through all the code constructs within a java class? Let's say I want to, for example, find all usages of OtherClass.doStuff() within a particular PsiClass
3) Even better than the above, can I call structured S&R programatically?