What happens to all finances in probate lawyers trust account

Have been going through probate since 2017 and since have had to sell two out of four properties due to taxes my grandmother law owed and according to probate lawyer the estate cant get closed because we are waiting for the IRS to approve a waver, but if we wait any longer in the mean time during the wait until irs approves the waver bills keep adding up are still interest,and on top of that more lawyer fees,Not to mention all the finances are sitting in one of the lawyers trust accounts and for every one new( bills that need payment gets paid through probate lawyer in which probate lawyer charges us for every bill,he pays every call,email he takes so I asked him just to pay the full amount that the estate owes in taxes instead of waiting any longer for the irs to approve the waver so that we can just close the estate and probate lawyer wont do that so my question is if I decide to fire this probate lawyer what happens to the rest of the finances that remain in lawyers trust acct.