Sorry if I get a few things wrong but it's been a while since I've effort posted and looked up USSR history so umm:

I think at that point it'll probably be too late to do anything. So much of the Communist Party has already been consolidated by revisionists and self-interested fucks, not to mention active subversion by the American intelligence apparatus and the failure that was Afghanistan, that it rendered itself impotent. Without a party to guide the people, they became aimless and disorganized, unable to organize themselves while the party crumbled under it's own incompetency.

You would probably have to go right after Stalin's death to ensure Khrushchev doesn't start with his secret speech bullshit and do what Stalin originally planned, to further democratize and involve the masses into their economy and it's planning, which would've rendered Party organization wholly irrelevant in the way that it existed while pushing the USSR to a higher phase of socialism. The way to do that would've been the All-State Automated System, or OGAS but by the time it was technologically feasible, it was denied funding because, of course, the revisionists felt it would threaten Party control of the economy at the time it was being opened up and liberalized.