let get on with
let (one) get on with (something)
To allow or permit one to continue or resume some activity or task. Thanks for explaining all that to me. I'll let you get on with your work now. They'd probably be finished with the project by now if you'd stop interrupting them and just let them get on with it.
let someone get on with something
to permit someone to continue something. I will leave now and let you get on with your work. She had to settle the matter first. She would not let herself get on with life until the matter was settled.