About two million people on the streets of Moscow should be enough for authorities to stop arresting people. Or how do you think Germany was reunited [1]? It is sickening to see people afraid of their government, the entity which exists to care for them and protect them.
Economic sanctions hitting the small man might be the best chance you'll get to see that happening. The only question is how much military support the government really has, lucky for us the USSR was busy collapsing so that gave a window of opportunity.
It’s nearly impossible to organize a large scale protest in Russia. All the opposition leaders were jailed or murdered and even just posting info about protests is a criminal offence. There’s also a problem with many people being indoctrinated by the state propaganda, because independent mass media is banned.
There was an ECHR decision ordering Russia to free Navalny, but it was ignored by Russian government and Council of Europe did nothing about it.
[1] https://en.wikipedia.org/wiki/Monday_demonstrations_in_East_...