Step one: kill the filibuster, and ram through numerous laws reversing the damage from Trump, protecting voter rights, reproductive rights, raising the minimum wage, etc. and most importantly, restricting presidential powers (like repealing the moronic law that gave Trump authority to implement tariffs after declaring a phony emergency). If this is done swiftly and fearlessly, and implemented in a way that quickly brings tangible benefits to working Americans, Dems can rest easy that Republicans wont use the extinction of the filibuster to undo it all without facing the wrath of the electorate (think how long Social Security has been the third rail in politics- Dems should create dozens of third rails- want to lower the minimum wage? Go ahead, make my day!)
Step two: expand and reform the courts, adding at least five new seats to SCOTUS, with tough, enforceable ethics rules that include suspending judges/justices from the bench who dont comply, without the need for impeachment. This way, the laws passed in step one cant be easily undone by the MAGA majority on the Roberts court.
Of course, this must be predicated on electing Democrats who are willing to do both steps one and two.