Liner installation Question Damper in the way

We are running into a problem. We have a damper, which I have attached a picture. That is causing a problem to pull the liner through to be able to attach to a stove, which needs a custom made attachment. Pre EPA Pioneer stove.

Do we cut the damper out? Otherwise it is a straight shot of clay lined chimney 13" wide. We are installing a 8" insulated liner.

Damper opening measurements: 5 5/8" x 32" long.

I know about doing a block off plate, just want to be sure what to do with this damper

Thank You all! We are having a hard time cutting it out. It seems it was put in with the build of the chimney so it is somewhat built in with the brick and mortar around it.

Well we have just about any tool available, tried with a sawsall. was able to cut out a piece, tried to hammerout around the cast iron and it did break up a corner of it. Angle grider the latch off, still working on the rest of it.
We have so many tools, just not sure what is the best for this project, a touch

Open to suggestions.

We have one of those and was using it. Might need to find the cut off wheels, the disk used was not a cut off wheel.

Thanks, we have a plan now. will get grinder wheels, we have them but dont know where we put them.

thanks for the pictures!