Form of summons to be issued and served upon the person impeached:

The United States of America, ss:

The Senate of the United States to ------ ------, greeting:
    Whereas the House of Representatives of the United States
of America did, on the ------ day of ------, exhibit to the
Senate articles of impeachment against you, the said ------ --
----, in the words following:

                       [Here insert the articles]

And demand that you, the said ------ ------, should be put to
answer the accusations as set forth in said articles, and that
such proceedings, examinations, trials, and judgments might be
thereupon had as are agreeable to law and justice.
    You, the said ------ ------, are therefore hereby summoned
to be and appear before the Senate of the United States of
America, at their Chamber in the city of Washington, on the --
---- day of ------, at o'clock ------, then and there to answer
to the said articles of impeachment, and then and there to
abide by, obey, and perform such orders, directions, and
judgments as the Senate of the United States shall make in the
premises according to the Constitution and laws of the United
States.

    Hereof you are not to fail.

    Witness ------ ------, and Presiding Officer of the said
Senate, at the city of Washington, this ------ day of ------,
in the year of our Lord ------, and of the Independence of the
United States the ------.

                                             ------ ------,
                                   Presiding Officer of the Senate.

Form of precept to be indorsed on said writ of summons

The United States of America, ss:

The Senate of the United States to ------ ------, greeting:

    You are hereby commanded to deliver to and leave with ----
-- ------, if conveniently to be found, or if not, to leave at
his usual place of abode, or at his usual place of business in
some conspicuous place, a true and attested copy of the within
writ of summons, together with a like copy of this precept; and
in whichsoever way you perform the service, let it be done at
least ------ days before the appearance day mentioned in the
said writ of summons.

    Fail not, and make return of this writ of summons and
precept, with your proceedings thereon indorsed, on or before
the appearance day mentioned in the said writ of summons.

    Witness ------ ------, and Presiding Officer of the Senate,
at the city of Washington, this ------ day of ------ in the
year of our Lord ------, and of the Independence of the United
States the ------.

                                             ------ ------,

                                   Presiding Officer of the Senate.

All process shall be served by the Sergeant at Arms of the
Senate, unless otherwise ordered by the Senate.

Source: From RULES OF PROCEDURE AND PRACTICE IN
THE SENATE WHEN SITTING ON IMPEACHMENT TRIALS, rule XXV

(taken from http://frwebgate.access.gpo.gov/cgi-in/getdoc.cgi?dbname=99_cong_documents&docid=f:sd33.wais)