What do you do to stop the counterrevolutions?
I would probably tell Poland to either reenact martial law or face mobilization of Soviet troops that are already stationed in Poland to hunt down the so called "solidarity" terrorists ourselves. Meanwhile, I would tell Hungary to close the borders again under a similar threat. Obviously I would try to prevent another 1956 but those reactionaries involved in that decision must be removed from power.
Meanwhile, at home in the Soviet Union, I would put a stop to Glasnost but probably continue Perestroika by turning it towards the Chinese model.
By 1989 the Soviet Union is already facing existential levels of economic collapse, societal upheaval, and general unrest within other Warsaw Pact countries. It would have taken a miracle to recover the country, and that's without the US bearing down on you.
The Soviets managed to overcome economic collapse, societal upheaval, and general unrest after the Russian Civil War. If it worked then, why not in 1989? You just need competent leadership and defeat counterrevolutionaries the same way the white movement was defeated.
Because the country still had a militant organizational structure fueled by communist fervor and Marxist dialectics. By 1989 no one cared about communism anymore and people's knowledge of Marxism was scattered at best; all they wanted was for things to "get better". People are going to blame the ones in power for their suffering, and there are no express "counterrevolutionaries" you can defeat and bring things back to normal, as the sentiment was ingrained in the collective mindset by 1989. You have to remember. That is the year the Berlin Wall went down, it was already the beginning of the end. Recovery would be a Herculean task.
The Soviet Union in 1924 had the benefit of decades of labour organization, grassroots education, collective identity, and struggle to build off of. 1989 Soviets did not have that. Or what they did have had been corrupted by liberalism for decades at that point.
Also how are you going to turn to the Chinese model? The Chinese model requires a market centered economy that dictates rapprochement with the West to fuel investment into the country. Do you think anyone in the West would ever consider investing in the Soviet Union? The Chinese model worked mainly because they weren't the Soviet Union.
they have newer and more novel ways to turn screws nowadays that they didn't have back then and they've also learn how to ensure that you can only learn of them the slowest ways possible so as to maximize their effectiveness through ignorance.