Hay peng....
You can do it.
If you change the address you don't need to fill the address change form (AC11)
What you will do is call IIo and tell her you changed the address and give your A# number and new address... That's it.
You don't need a lawer to file AC21... Generally you can call IIo and change it. Since it contains more info.... It is hard to tell in phone and required proofs... That is why
1. you fill AC21 form old company to another new company,
2. new employment letter - Have a same description and title is better, it won't rise any questions in future. (for Evidence confirmation) and
3. pay stubs if you have (one is enough). Have a same salary or near that number is good, it won't rise any questions in future. (for Evidence confirmation)
4. New comany address confirmation...etc (for Evidence confirmation)
5. If you send your change of address is also very good. So that they will update their records with all changes.
YOU WON'T EVEN GET RFE If you do this. It is a process guys, it is not some thing
Combine them and send.
Generally speaking, They won't look how much you are making and unnecessary stuff. It should not be below the (state and federal law) Govt standard. that's all.
They just want to confirm whether you are true or fake....
Take care man.