Any tips for removing the chimney damper to fit 6" stove pipe up?

[Solids]

Recently bought a used Buck model 81 non-Cat that is about 13 years old. Great fit as an insert for our well-hearthed fireplace but despite a 13x13 chimney opening (that we need to line), the damper only has about 5" of opening and that is if you go in at the 45 degree angle that the door slants on. It is built in to the chimney (or so it would appear, no movement and no visible attaching hardware when I get in there with my headlamp and mess around with it.)

I have heard some options ranging from sawzall (cut the whole thing out)to cutting torch to an offset grinder. I like the idea of the grinder to just get a small half-circle cut in on the non-door part so I can fit a 6" flex through it, but I defer to the experts here for comment and suggestion.

Thank you in advance from someone who has been lurking and benefitting from the info here for a while.

 

[r_d_gard]

I just did this in October last year.

If you are handy with a gas axe then that would be the easiest route.
I did it with a sawzall, a good supply of ear plugs and safety goggles. It was a real doozy being all curled up in the fireplace to try and trying to cut it out. Therefore the gas axe would be the easiest. The hardest part was taking the damper completly out. Cutting the back out of the fireplace was a relatively easy. You probably don't want to "ovalize" your chimney insert as this affest the crosssectional area of the liner, thereby affecting your draft.
I'll shove the camera up the fireplace and take a couple of pics for you and post them after the kids are off to bed.
Any way you do it, it's a real messy job.

Ray

 

[cmonSTART]

When removing a damper I typically use any of the following:

Sawzall
Rotary Hammer
Masonry Chisel
Hammer
Pry Bar/Wonder Bar
Screwdriver/nut driver

Really just get in there and work at it until its out. Remove the damper plate first though.

 

[BrotherBart]

Just use a hacksaw. Really. I went through grueling hours of the Sawzall and all of that other crap and then got mad and went to the garage a grabbed a hacksaw and twenty minutes later it was done. The stuff cut like butter with the thing. Cut a slot on either side of the opening you want and then whack the flap with a hammer. Badda boom, badda bing. Done.

I needed dental work after hanging onto that going nowhere Sawzall. :shut:

 

[Solids]

My lazy answer alter ego says " I was hoping someone would say to just buy an adapter to get through the opening, and you can get it here______"....it seems like I am getting the same mixed info as to personal preference. Which is fine but I was selfishly hoping for an 'out of the box' idea.

Thank you all for the input. The more knowledge, the better, IMO