Many people do not notice that since this is a very special case. An INS lady did not even know that years ago when I asked her.
I would suggest you fill out those forms by yourself. A lawyer does not really help, at least in my case. I almost did everything by myself and paid almost $2000 which is actually the lawyer's tuition.
If you are going to do it by yourself and have questions, you may drop me a line. I will see if I can help.