Impeach for Peace has put up a brilliant Do It Yourself impeachment form. They've done the research, set it all up for you. It is indeed legal, with precedent, to citizen-initiate the impeachment of a federal official. More, from their site:

Impeach for Peace, a Minnesota-based impeachment group, has researched a method for impeaching the president using a little known and rarely used part of the Rules of the House of Representatives ("Jefferson’s Manual"). This document actually empowers individual citizens to initiate the impeachment process themselves.

"Jefferson's Manual" is an interpretive guide to parliamentary procedure, and is included (along with the Constitution) in the bound volumes of the Rules of the House of Representatives. The section covering impeachment lists the acceptable vehicles for bringing impeachment motions to the floor of the House.

Before the House Judiciary Committee can put together the Articles of Impeachment, someone must initiate the impeachment procedure. Most often, this occurs when members of the House pass a resolution. Another method outlined in the manual, however, is for individual citizens to submit a memorial for impeachment.

After learning this information, Minnesotan and Impeach for Peace member (Jodin Morey) found precedent in an 1826 memorial by Luke Edward Lawless which had been successful in initiating the impeachment of Federal Judge James H. Peck. Impeach for Peace then used this as a template for their "Do-It-Yourself Impeachment." Now any citizen can download the DIY Impeachment Memorial and submit it, making it possible for Americans to do what our representatives have been unwilling to do. The idea is for so many people to submit the Memorial that it cannot be ignored.

Feel free to download it, print out TWO copies, fill in your relevant information in the blanks (name, State, etc.), and send in two letters today (One to the Speaker of the House, and the other to John Conyers of the House Judiciary).

Hold on to the other copy of the two letters until October 12th when we're having everyone send them in.

That's right — to make a big impact, we're having everyone send it in on the same date. We hope to flood the Judiciary Committee and John Conyers office with sacks of mail and cause a newsworthy event to further pressure the Congress to act on the memorials. Although, it's important to keep in mind that in the 1826 precedent, impeachment resulted as a result of a single memorial. Yours might be the one.

And while you're at it, you could pick up one or a dozen of our spiffilicious Impeach The Mother Fucker Already (ITMFA) buttons to promote the cause (50% of all ITMFA proceeds are donated to MoveOn.org to support progressive activism):