Milltek themselves have a general fitting guide.
http://www.millteksport.com/general.exhaust.fitting.instructions.cfmI'm not sure that I have seen any 'How to' on this forum about fitting a Milltek to a Mk5. However, there is one on fitting a Pipewerx to a Skoda Octavia and the principles are the same, I guess:
http://briskoda.net/forums/topic/124442-tfsi-downpipe-fitting-guide/It is not a difficult job as it is essentially 'just nuts and bolts' after you get the car up on ramps and the plastic tray removed from the underside and the engine cover off if you have one.
There are a few tips from my point of view, again from a Skoda Octavia perspective but its the same deal:
- A fair bit of force and a big socket/torque wrench for plenty of leverage may be needed to remove the existing DP. A good overnight soaking with WD40 should assist. This is where the only real danger exists i.e. inadvertently snapping one of the the threaded studs holding the DP on although that would be unlucky! Sometimes some tightening force rather than just diving in with high loosening force helps break the binding i.e. give the nut a bit of a wiggle
- You need long arms to reach behind the engine to get to the bolts and one of the bolts is accessible but out of sight so you need to feel around and loosen it blind - an inspection mirror may help. Also protect the paintwork on the wings from buckles, zips, etc as you lean into the engine bay (obvious perhaps but I learned the hard way!!)
- In my case the top 02 sensor needed to be unclipped from the wiring loom but had to come down still attached to the old exhaust and then be removed. The geometry of the new DP (in my Pipewerx case!) meant that there was more room and the sensor could be reattached after the new DP was fitted
- Check that the support prongs on the Milltek line up with the holes on the mounting bracket on the underside of the car (remove the bracket). I don't think it is an issue with Milltak but mine had to be bent out about 10mm to fit and that would not be easy if the exhaust was attached.