We just purchased a house with a BIS 1.2. The grate is gone in the middle due to overheating it looks like. I ordered a new grate online but I am wondering how to install it. It has 2 tabs on either end on the back which need to go through the sides so it hinges up when you lift it to take out the ash pan. Is it as simple as removing the side refractory panels to insert the tabs through the sides?? Thanks for your help.