Go to his homepage, under 'How Can I Help'. Then 'Federal Agency Assistance' > Immigration Help.
Fill out the form, once complete you can print and fax it to the number specified. Make sure to write urgent on the form before faxing.

On the form I explained how my case was beyond the posted processing time, how I lost my job due to my EAD expiring, etc. One of his aids should contact you shortly via regular mail.

I suggest you exhaust all your options before going this route, such as putting in a service request, contacting the Ombudsman office.

Let me know if you have other questions.