Changing a name??

[newmom81]

OK I am in removal proceedings and my next hearing (next year) will be focussed on approving my application for permament residence in USA. I am very confident I will be approved, I have approved VAWA and USCIS lady at my last hearing told judge they do not see any reason why my I-485 should be contested.. The thing is that I will get re-married in September and I want to change my last name to my new husband's, so that me, him and our 2 children have the same last name. Also I plan on adding a middle name to my official documents since none of my US documents shows my middle name. I might do both name things just by a local court order. My question is, if I can do the name change and then take the name change documents to the immigration hearing so when the judge approves my I-485, the green card will show my new name. Or do I have to wait with the name change AFTER I get a green card and then pay a lot of $$ to have it replaced? Please help. My concern is that if I change my name now and then wait 8 months to take the papers to my next hearing I might get told I did something illegal by not letting them know right away... but there are no name change forms I can file with immigration as far as I know.