The CCV is a pain in the arse to access, located at the backend of the engine compartment in front of the driver/firewall. You will have to disassemble practically everything on that half of the engine bay to get to it (took the indy shop 5h of labour). Setup is nearly identical to that in the E46; don't forget to replace the hoses as well.

However, a variety of other things could cause those lean codes: intake boot leak, DISA valve, CCV, possibly other items.