Disconnect the power rods from any cable hooks that you might have connected. Just pull down on the rod, and then lift the hooks away.
Tilt the Bowflex Xtreme 2 SE slightly to one side, so you can access the area underneath the box of power rods. You will need someone else to hold the machine in this position while you work.
Remove the three screws located directly underneath the power rod box. Lower the Bowflex back to its normal position once the screws are out.
Slide the power rod box backwards and out of the machine.
Pry up the hole covers over the first two empty holes in the box.
Insert the two rods that came with the 310-pound power rod upgrade into these two slots. Lay the box on its side and screw the rods into place through the bottom of the box. The upgrade kit should have come with the required screws. Return the box to an upright position when you are done.
Position the two connected rods that came with the 410-pound power rod upgrade kit over the rear of the box. Line up the ridges on the front of the upgrade rods with the slots on the back of the box. Lower the upgrade rods into place.
Slide the power rod box back into place on your Bowflex Xtreme 2 SE. Tilt the unit to one side again, and screw in the power rod box.