1) Open the front door - the message ’Cover is Open’ will appear.
2) Press and hold the cancel button.
3) Press the Reprint button - the message ’Reset Parts Life’ should appear.
4) Then do the following:
B.TNR-H - accepted should display. Press ^
B.TNR-S - accepted should display. Press ^
Y.TNR-H - accepted should display. Press ^
Y.TNR-S - accepted should display. Press ^
M.TNR-H - accepted should display. Press ^
M.TNR-S - accepted should display. Press ^
C.TNR-H - accepted should display. Press ^
C.TNR-S - accepted should display. Press ^
5) Cancel
6) Close the front door.

You should be able to print, assuming your HL-4070cdw still has toner and drum life left.

I believe the above sequence clears the toner for Black, Yellow, Magenta and Cyan for the High capacity or Standard capacity toner cartridge.

None of the stats for your printer will be reset (ie Image Count, Drum Count, Drum Life, Belf Life, PF KitMPLife, PF Kit|Life, Fuser Life or Laser life) and your print totals will still be unchanged (ie Toner page count, color page count, monochrome page count).