audacity 2.1.1 on a macos sierra 10.12.4 - removing vocals

Hi, i use Audacity to change pitches, slow tracks etc… I’ve ever been able to remove vocals to produce a clear instrumental (if i cannot already by online as old track etc…) I’m not sure if i remove middle, vocal reduction, isolation etc?? I’ve tried but you can still hear vocal in background etc… i really need a step by step please… Thank you.

Please understand that removing vocals is not a given when all you have is the mix. You are trying to unbake a cake.

See: for some methods you can try.