How do I hard wire new oven to existing wires?
Remove the clamp -- cut off the clamped end and restrip the neutral if you have to

If the clamp is too tight, you may have to cut off the clamp and then strip the insulation from the cut end of the neutral.  This is mentioned in step 8A of the install instructions for your oven:


  Free the neutral (white) lead from being restrained to any other
  wires. If necessary, cut the neutral (white) lead and then re-strip
  it to expose the proper length of conductor.


From there, it's a matter of attaching like to like with the wirenuts -- red goes to red, black to black, white to white, and bare to bare + the box ground pigtail (bare or green) if there is one.  If there isn't a box ground pigtail and the box is made from metal -- get a bag of 'em and screw the screw-end into the screw-hole in the box, then nut the wire-end in with the bare wires.