Please note: I have no qualifications in Anglo-Norman, or in fact in any form of French. The following translation is intended as a fun exercise, not a rigorous scholarly undertaking, and accuracy and finesse are in no way guaranteed.
Anglo-Norman Letters and Petitions IX, p 8: J. de G. and others to Henry IV.
To our most high, most mighty and most redoubtable lord, our lord the King: if it be your pleasure, we, J. of G., the gentles and commons of [the counties of] W. and T. and certain people of K. represent that, as we are become your loyal subjects and tenants and we have submitted ourselves to your most high and excellent grace and will thus, may it please your most gracious lordship to pardon your said poor and humble gentles and commons of the counties aforesaid our insurrection and rebellious and to accept us along with our lands, goods and holdings and to receive us as loyal men and subjects beholden to you and to no man else, save to our most redoubtable lord the prince, your most gracious son, etc.
Original text from Anglo-Norman Letters and Petitions from All Souls MS. 182, ed. M. D. Legge, Anglo-Norman Texts 3 (Oxford: Anglo-Norman Text Society, 1941). 8.
 Judging by “the counties aforesaid” below.
 Or rebellion - “rebelté” could be either.
 “pardonner... et nous acceptee” - I can't find any way to read that except as a scribal error for “accepter”.
 “loialx et liegez tenantz a vous” - “loialx et liegez” could be nouns and “tenantz” the adjective, or the other way around: “loyal men and subjects beholden”, or “loyal and feudally bound tenants/subjects”. The phrasing echoes “loyal subjects and tenants” earlier (“loialx lieges et tenantz”).