You can have a read here Henry.
Upgrading 2nd generation headunits (RCD 300, RCD 500, MFD2) to 3rd generation headunits (RCD 210, RCD 310, RNS 310, RNS 510, RCD 510)
There are loads of tips and tricks on that site.
Upgrading 2nd generation headunits (RCD 300, RCD 500, MFD2) to 3rd generation headunits (RCD 210, RCD 310, RNS 310, RNS 510, RCD 510)
There are loads of tips and tricks on that site.