Do a new trilogy set an indistinct number of years after the original. (Not explicitly period, but cell phones and late-model cars will be conspicuously absent).

Keep the events of previous films indistinct as well - don't mention specific years or characters, just say "many years ago this guy escaped from the loony bin and stalked and killed a bunch o' girls."

Introduce a new group of characters, separate from either the Strode, Loomis or Myers bloodlines, that we can follow through this new sequence of films. This series has always leaned heavily on its characters and mythology - it's time to start creating new ones instead of endlessly circling back to the old.