In short, you don't. Canada doesn't have an inheritance tax, so beneficiaries generally don't pay taxes on what they've inherited.
The deceased person's legal representative is supposed to file a deceased tax return and make sure the estate pays or secures to pay any tax owing before the inheritance is given over to the beneficiaries. By the time the estate is settled, the beneficiaries should not have to worry about taxes.
Certain exceptions are possible if an eligible person has been designated the beneficiary of an RRSP or RRIF.
Check out our Canada Inheritance Tax Laws page for more information.