I can think of at least five things to do if Trump fires Robert Mueller.
1.) Celebrate the beginning of President Cheetohead's demise.
2.) Call your House and/or Senate representative and demand they hold him accountable. We need more than six Democrats this time, including all those Republicans who warned Trump not to cross this "red line." Both sides of the aisle need to get on board this train.
3.) Protest! Protest because the same man who vowed to "drain the swamp" has instead taken all that swamp water and built a moat around the White House, using his own racist bile to refill it regularly.
4.) Call everyone you know - even your Trump loving friends (if you still have any). Remind them of what happened the last time a sitting President tried to fire every single person looking into his misdeeds. Tell them it's time to get rid of the unstable mental midget at 1600 Pennsylvania Ave.
5.) Pop some champagne. The long nightmare is finally coming to its inexorable end.