Keep all the dissidents there. And especially all the able bodied men now trying to get out. Let the protests rise and continue. Eventually the Generals will see Putin as the catalyst and sacrificial lamb.How Russian gt rid of Czars? Three things: (1) It was not such totalitarian regime as now, (2) The police ability to control what people are doing was much lower, and, most importantly, (3) lots of help from Germans .
Any suggestions on how it can be done internally?
Add in continuing to supply arms to the Ukrainians. Keep up the pressure. And offer Russian Soldiers, and only Russian Soldiers, asylum. That way they expend resourses and lose men and equipment. Pay Elon Musk to get his Satalites over Russia the way he did in Ukraine and is now doing in Iran. If possible supply smartphones to Russian citizens so they can organize.
But in the end it has to be Russians that do it. Anyone else is an occupying force.