My back insulation board is cracked in a few spots. Any idea if this can be replaced from the top without disassembling the stove? I found the insulation board moved forward and was blocking airflow to the stove. Particulate matter dropped from the 8" chimney pipe and pushed the insulation board forward. Or can this be pushed back into place with stove cement? Thanks....bought the stove new 12 years ago and it has been flawless until now.