Hi all,
Before you point out my stupidity I'm well aware I've stuffed up.
Basically one of my exhaust studs snapped so I went about removing it with an EZ out tool. But while I was doing that a length of metal about a centimetre long and a mil or two think that was drilled out fell into the exhaust hole. My question is has anyone done this? or had any other obstruction fallen into there. How would you go about getting something like that out? I'd prefer not to have to pull the engine apart as to be honest I'm not confident in my ability to do it. Any advice would be appreciated.

Hopefully the exhaust valve was shut, otherwise you may be in the crap.

Easiest way is to braise an air fitting onto the top half of a spark plug so you can screw it in and pressurise the cylinder with LP air, if you do this without moving the engine, you will know it was open or not. 

Them turn it over (if she was shut) , preferably by hand, other plug removed, in 6th gear back end raised.

The exhaust valve will open and the shaving will be blown out, if you are doing a job like this you rig it up first and have air blowing out the port before you start drilling etc.

Trouble is if the valve was open there is a chance it has one down into the cylinder, someone with more experience on the cylinder head, exhaust port and valve design may be able to shed more information.

This method of using air pressure can be used to do valve stem seals without removing the head (provided the rings are good), or you feed a shit load of rope (not one tail ! you hang onto that one) into the cylinder with the piston at BDC then wind her up and compress the rope up under the valves, works a treat :)

Could try fishing it out with one of those little magnet on a flexi shaft tools, even if it's gone into the barrel, stick it through the spark plug hole, you might be lucky. 

Thank you all for the suggestions.
It's a shaving from the stud not the head which does mean I can get at it with a magnet.
That being said it was so seized the easy out didn't work so its looking like a helicoil will be required anyway.
I was fishing around in there last night with a flexi magnet through the plug and got some out (which means the exhaust valve was open) but I'm afraid there will be more so the plan is to do the vacuum on the end of a hose trick and then take a look with an inspection camera. Hopefully if I find nothing with the camera then its not hiding somewhere I can't see. Funny how something so simple as changing the exhaust can turn into such a massive PITA. Especially when you make silly mistakes.

Not what you want to hear , if it was mine ,the head is off ,its the only way to be certain there is no contaminant .

I would be too worried not knowing if I had 100% of the metal out so would take the head off it

OK, so I suppose this is where I start asking stupid questions. Like can the rear head be taken off without pulling the engine? It's a 2003 xl883r.
I've got the manual and I'm reading through it to gain a better idea of whats involved.

Take the head off and use a TimeSert for the thread (IMO Helicoils are rubbish)

Thank you all. The previous owner gave me a full gasket set so I went about very slowly pulling the head apart just to get a look at it. Turns out I got everything with the magnet and camera but good to know none the less. New gaskets and it's all back together. Ended up drilling the bolt out incrementally till it was all gone and then drilling, tapping and Helicoil in the head. New stud went in a breeze after that. It's all back together, exhaust is on and I've had a few rides. So far so good. I'm not convinced I don't have an exhaust leak at the head but that's probably just me hearing every tick and noise and thinking the worst. I've done every exhaust leak check that I've looked up online and couldn't fault it. So I suppose happy days. Thank you all again for all the advice.

Good to hear you are getting it sorted mate.

Well done, just ride it and enjoy

Well done! Good result