leave/let well alone

let well alone

To refrain from changing, disturbing, or becoming involved in something so as to avoid unintentionally causing (or worsening) problems. To be honest, you're better off letting well alone at this point. She's so angry that anything you say will just make things worse. Messing with the registry can cause catastrophic problems for your computer. If it isn't already totally busted, I would let well alone.
See also: alone, let, well
Farlex Dictionary of Idioms.

leave well alone

If you leave well alone, you do not interfere in something, because it is all right as it is and you might make it worse. He knew when to leave well alone and when to interfere. Gordon knows his business, he says, and I should just leave well alone.
See also: alone, leave, well
Collins COBUILD Idioms Dictionary, 3rd ed.

leave well alone

refrain from interfering in or changing something, for fear of making it worse.
See also: alone, leave, well
Farlex Partner Idioms Dictionary

leave/let well aˈlone

(British English) (American English let well enough aˈlone) not try to change something or get involved in something: Arguments between other couples should be let well alone.
See also: alone, leave, let, well
Farlex Partner Idioms Dictionary
See also:
  • leave well (enough) alone
  • leave well alone
  • leave well enough alone
  • let well alone
  • let well enough alone
  • leave good (enough) alone
  • knock someone out
  • knock something out
  • knocked out
  • knockout