Remove heatilator fire box floor to level with hearth

[JordanFrame]

I'd like to install a Harman accentra insert into my prefab fireplace. Problem is the ZC firebox floor is about 4 inches higher than my hearth. The Harman ZC box accessory directions advise to address this by removing the firebox floor down to the bottommost sheet of metal (see below). Has anyone done this before? Concerned about destroying the existing firebox without knowing what I might find. Here's the text from the Harman manual. I've also attached a pic of my ZC fireplace.

From Harman install manual:
"The second option is to
lower the firebox floor by removing sheet metal (A), refractory (B), and
insulating materials (C), along with the front lip. Remove the fasteners that
are holding the inner panels together or cut them down to the outermost
layer of sheet metal at the bottom. The existing inner sides and inner top ygp must be left intact."

 

[Sodbuster]

Jordan, if it were me, I would use a 4" angle grinder with a metal cutoff wheel on it. cut straight down flush with the side pillars, leaving them intact. From there, I would think you could remove the front metal lip, which would give you a better idea of what's going on underneath. Just go slowly, and think through each step.

 

[JordanFrame]

Jordan, if it were me, I would use a 4" angle grinder with a metal cutoff wheel on it. cut straight down flush with the side pillars, leaving them intact. From there, I would think you could remove the front metal lip, which would give you a better idea of what's going on underneath. Just go slowly, and think through each step.

 

[JordanFrame]

Great advice. I agree completely--already had pulled out the angle grinder.