As expected that was a bitch of a job. But it went in without having to remove bricks half way up the stack. For others contemplating the job and wondering if the 6 inch liner [1] will go up the flue here are my experiences. I have a standard 10 inch flue 6 mts long with 2 restrictions [2] 90° to each other - one left to right and one front to back - height of restrictions about 24". I decided to pull the liner up, since any problem with a liner half way up would just leave the rest in the room rather than rendering the situation more urgent by it dangling in the air and quickly being destroyed over the chimney top. Get a nose cone - mine was a bit blunt and it will catch on everything on the way up - especially at any restrictions. So get a pointy tapered one if possible. I self tappered it one and then wrapped about a yard of real gooey tape around liner and cone. I used 8mm climbing rope to haul it up. Make sure you can't break whatever you choose and something good and thick like my choice is advised or you'll cut your hands to pieces. You will most likely have to haul like a person possessed, so make sure it is on really securely and devise system of hauling. I found short explosive bursts worked best. Essential to have 2 people at either end. I stood on a ladder and reached right down the flue to haul - this meant I was confident any cone detachment wasn't going to throw me off the ladder. As the liner reaches the top I sat 'à cheval' atop the stack. Be certain you can't fall off the stack after an unexpected cone detachment!! The other person must guide and push simultaneous with your pulls so as to ensure minimum friction and as much pushing welly as they can muster.
Time req'd ~ 1 hour.
I dispensed with the 1mt trial section malarky and the gamble paid off. YMMV!! Now I can confidently go buy the stove with the worst behind me (I hope).
Have fun
[1] required in the regs for non-smokeless fuel [2] I've called them restrictions but really they are changes in the vertical flues axis position, shifting round a 1st floor fireplace and out into the external stack..-- Mike W