how to remake my characters?

Could you give me an advice how to start playing with this new skilltree? I have 3-4 high lvl character, but i did not play for a while, and i'm not really up to date about strong setups. I'm afraid that if i just remake all my characters fast, i will make big mistakes :(

is there a comparator where i can compare my old builds to a new build? Or are there good articles about buffed and nerfed passives/gems? Can you give me any advice? I looked for new setups but i dont know which of those are good and which of those are bad. Also, i know that i want CI crit dagger shadow, 2h blunt marauder, and heavy summoner witch, so i am quite specific.