I need to get a birth certificate for my late mum as I need it for some processing. Does anyone know how I can get that done?

You can easy get a death certificate for her not Birth certificate since she's late. Unless you claim she's still alive.
For international purposes, you'll get it through the following process:
You need her passport Photo, her elder bro/sis or older person's passport photo also & he/she will attest for her at the high court to get Declaration of age which you'll take to Nigerian Population Commission (NPC) to get the Attestation of Birth Certificate.

Thank you.

Thank you

Nancyama:
You can easy get a death certificate for her not Birth certificate since she's late. Unless you claim she's still alive.
For international purposes, you'll get it through the following process:
You need her passport Photo, her elder bro/sis or older person's passport photo also & he/she will attest for her at the high court to get Declaration of age which you'll take to Nigerian Population Commission (NPC) to get the Attestation of Birth Certificate.