It depends on what the problem is.  Retained Earnings normally has a beginning balance and after that is simply calculated from the net of income and expense accounts when year end routine (AM-B) is run and updated if transactions to income or expense accounts are backdated to a prior year.  If both the balance sheet and trial balance are out of balance and you know the difference belongs in Retained Earnings then you can use UT-A, program EDITGL and create a one sided entry, then UT-K-D and recalculate the account.