As the desired character, progress through the prologue until you are about to enter the bridge area. Now quit the game and have a friend set up a multi-player session, ideally near Paradise or Halai. Enter that game and choose the same character as you had been using to play through the prologue. Find Henry Boyle and transfer all equipment and weapons, except for a couple that you don't care much about. Quit the game and then resume your efforts in the prologue. Finish that segment and start working through the first chapter. When you reach the Paradise area, look up Henry Boyle again. You can reclaim your belongings that you had in the prologue.