AllBbear, I truly don't think you need a lawyer. You can start the application at the
Mexican Consulate in DC yourself.
I could be wrong about this, but whether you have a lawyer or not you are still going to have to appear at an INM (Instituto Nacional de Migración) office in Mexico to finish the application and actually get the card. I suppose if having a lawyer would eliminate the in-person visit to the INM office in Mexico it might be worth it, but I can't imagine INM not demanding an in-person visit, representation or not. Perhaps some here can enlighten us on that subject further.
The consulate in DC will verify your income and the other documents required, which are listed on the DC Mexican Consulate's web page the link will bring up. It's in Spanish but you can muddle through with translation software, and you can call them: (202) 7361008. There may be an English version on the DC consulate site, but you can research that yourself.
At the INM office in Mexico they will give you a login to their web site where you can watch the internal steps towards getting the visa as they are completed. When it's time to come back, they will post a message for you to appear again.
The entire process of getting a residente permanente visa only took me 32 days from the first visit to the Mexican Consulate in El Paso, TX to picking up my card at the INM office near the Cordova Bridge in Ciudad Juárez. It involved 1 trip to the Mexican Consulate, and three trips to the INM office in Juarez during the 32 days.
The fees I was charged amounted to $38 US to the Mexican Consulate, and $3800 pesos to the INM office in Mexico.
It was a pretty smooth process, and at no time did I feel I didn't understand what they were asking of me.
There were a lot of details involved, of course, but your question went to the need for a lawyer, so no need to go any further at this point until you post more specific questions.
Good luck! The process for me, at least, was no big deal at all. And welcome to the forum.