Best bet is to use/borrow/steal or........ DEEP breath.......BUY a high temp. soldering gun. Get the cheap kind unless your planning on plastic welding alot. Dont get the akward feeling kind w/lights and pistol gripped handle and trigger. First Cut off little thin strips of material from unseen or unstressed parts of the bumper.(make sure its the same material!!) Long thin strips work best. Next, assuming the bumper is removed or easily accessed, tag the outer most edges of the broken piece with super glue/hot glue or some thing that cures quickly.(even tape??) Make sure the gun is at its highest temp. and begin by pushing the tip all the way through the center of the break. While pulling the tip out of the smoking, melting, and hella hot hole, push the plastic strip you cut, in the hole against the hot tip. You should push'n'pull slightly as you guide the tip out, constantly adding extra material into the melted mess. Repeat this along the entire length of the break including the edges of the broken piece being careful to remove the tape/hot glue. If you used cryno(super glue) make sure when you weld those spots that your clear of the highly TOXIC fumes that shoot out a little with the heat from the gun. Take care to avoid the smoke getting in your eyes, it burns like a motherf*&%er.(happens to me way to often) Make sure to let it cool completly and level, by level I mean level with the rest of the bumper...as stock would be. The welded strip itself should have a pronounced lip of excess plastic that was applied. Take sand paper or whatever your used to and shave/remove the excess plastic or lip. Youll know if you heated the plastic enuff to weld it together when you smooth out this area. Redo it if it begins to chunk or flake off. Keep practicing in your spare time. It sounds AAAALLLOOOOTTTT harder than it really is, but youll thank me in the long run...........you can fabricate ANYTHING out of plastics, and totally by your own hands!!!!! Good luck and feel free to E-mail me.....Im working on an NSX rear apron that needs an exaust outlet deleated because of the turbo that now resides there. Ill get some pics while Im doin it to show you better before you attempt to do it!!