If you go onto the Bosal site, you can see what the beast looks like:
http://catalogue.bosal.com/pages/ex...ake=fiat&model=stilo&body=&cartype=1.4&fuel=B
I'd recommend you first buy the pieces you need based on the Bosal chart;
The flexi section - 700-131 - looks available separately, if you need it. If you're not sure about it, or if yours looks remotely shonky, I'd change it anyway since it will probably be terminally rusted to the mid-section and it really isn't worth trying to separate them.
The mid-section- 286-115 - fits over the end of the flexi-section with a clamp.
The silencer - 148-345 - fits over that, with a clamp and is supported by a rubber hanger - 255-203.
I would have a very close look at your rubber mounts. If yours look perished or cracked, buy new ones. They're about £3 each from eBay or Halfords. The "225-112" (x 2) are the ones that do most of the work. The 255-203 (rear silencer hanger) could be okay but again.. if it looks perished, now is the best time to replace it. They're a bit dearer since they have a metal clamp attached... but circa £10 from fleabay:
http://www.ebay.co.uk/itm/FIAT-STIL...470199?hash=item3ab0181037:g:cPYAAOSwu4BV1KcA
You will need TWO new metal clamps - 250-258 in Bosal terms but again, Halfords etc. always has them in stock @ £3 - £4... Yours will be rusty/PITA to remove so don't re-use them.
You will also need a new gasket (between flexi and manifold) if you're replacing that piece.
The easy way to do it is by inviting Her Majesty, Grinda, Queen of the Workshop to the party. Use Her Majecty (the angle grinder) to cut off the rear silencer, wherever is easiest to stuff in the grinder. Then drop the silencer off it's rear mount/rubbers and pull it out.
Unbolt the front/flexi piece from the downpipe. The bolts will likely shear off (so get hold of some new bolts M8x35mm or thereabouts before you start - Halfords again). Unhook the front piece from its mounts and then pull it out. Don't bother trying to separate the middle silencer from the flexi piece on the car. Do it now (if they *can* be separated without wrecking the flexi).
To fit the new exhaust, bolt the flexi to the downpipe, using the new gasket and the new bolts. Fit any rubber mounts.
Slide the central silencer into place and hang it from the mounts. It should have enough movement for you to then be able to slide it over the end of the flexi piece but before you do that, put some exhaust jointing paste (or something like gun gum) over the last 1" 2.54cm of the flexi piece, so that when you slide the pipe over it, it will coat any space between them. Fit the U-clamp and tighten it up.
The silencer goes in from the back. hoist it over the axle and then hang it in place as before. Make sure the tail pipe is horizontal l if you have a shaped tail pipe. Again, coat the last inch of the middle silencer pipe with some goo and then manhandle the flared end of the rear silencer pipe over it. Now fit the rear hanger (the expensive one) .. then fit the U-clamp over the joint and tighten everything up.
Next.. depending on your rubber mounts.. give the beast a good side to side shake and see if it hits anything or moves excessively. If you have floppy rubber mounts, you can tighten them up by fitting a cable tie around their outer edge and compressing them a bit.. but with new/correct parts, the beast should be pretty rigid. Job's a good 'un.
Ralf S.
