UPDATE:
Replaced the Leak Diagnostic Pump (DTML) with an $80 Bosch pump I bought from EBay. Reset the code with the AWESOME BMWhat OBD app and problem solved!

Very easy DIY. On the E70 4.8 it's above the right rear wheel. Just remove the wheel, wheel well body trim and wheel well cover and it will very obvious. You'll have to remove the 2 10mm nuts to lower the entire charcoal canister to get at the pump for removal.

Very easy.