TN Visa Application without help of lawyer or outside firm

This will be my second TN Visa that I am applying for. My first TN was a few years ago and everything was done by my employer and everything went smoothly. I believe they hired an outside firm to do some of the work and put some of the pieces together. I successfully got the TN.

Now, I am going for a new TN Visa. Time is off the essence, and was wondering if I could put all of the documentation and employment letters stuff together myself without having a lawyer or outside firm doing it.

Is it possible? Does an outside firm or lawyer provide some extra "punch" to the application and maybe make it seem more legitamte to US Customs?

It's more of a matter of time - I don't want to wait weeks for a firm to complete this request. I'd like it done in a matter of a day or two. (Partially, it's money, but I'd pay a little if it were needed)

Thoughts?

I was able to get a TN without the help of a lawyer or firm, the only catch is that I received help from a friend that went to a lawyer for their TN. It was a great help for format and what type of content should be in my application and I worked with my employer to complete my final package I handed to the border. Seeing as you have obtained a TN before, just use your old application as a guide and do a little research online. You could always go to a lawyer in the event you get denied but your schedule may not be that flexible...as you have stated.