How?

Step one is to not do self-destructive things like vote down the CR and precipitate a government shutdown.

Step two is to allow the GOP to own the inevitably bad consequences to Trump's chaos, rather than taking ownership of it by contributing to the chaos.

Step three is to recruit and support candidates in swing districts that are centrist enough to win a purple electorate, and to do tamp down the more extreme elements of the national party that advocate performative stances on unpopular measures that make it harder for those folks to win races. Excellent example from the GOP - what Trump did to the hardcore pro-life movement. They want their leaders to "fight" also, and wanted to get the national party to take an affirmative stand in favor of measures that would prevent abortions in blue states - and Trump basically declared that was a stupid and politically self-destructive idea and told them to F off, wrote all that stuff right out of the national platform.

Win the House. Don't focus energy on primarying safe seats in the Senate, don't spend time on internecine warfare over whether the country is ready for a hardcore progressive party (it's probably not). Capitalize on the general thermostatic trend among the electorate to turn out the party that's been given a trifecta, get good candidates and give them the room they need to run a race that can win in their district.