Dad dies and stock of closely held business plus cash and marketable securities end up in Family Trust for Mom, two daughters and two sons.
Corporate trustee can make discretionary payments of principal and income to all.
Have them get their remainder interest now in exchange for an agreement waiving all interest that they have in the trust. My research says that the time and manner of distributions can't be changed. Note that we are not trying to correct a drafting problem, per se. Note also that the remainder interest of the sons is contingent on them surviving Mom. Your thoughts and insight would be greatly appreciated.