I guess I'll say… talk to the players (and their old GMs, if any), find out if they understand and can play in the style you desire.

If so, reboot.

Ideally, talk to them about what it will take, then run a few one-shots in a shotgun pattern around that general target.

Then talk to them again. See what worked, what didn't.

Repeat until everyone is happy, increasing to short adventures and eventually a campaign when you think everyone's on the same page.