scott froid

1980 400 XS. I have a seperate five wire regulator and three wire rectifier. If I want to replace both with one unit do I just wire the old rectifier (three white, one black, one red), to new combo unit and then old regulator, ( black, green and brown), to the new unit? So I am just rewiring two units into one. Thanks for reading. There are only two wires for the regulator on the new combo unit, the old one has three. Do I ground the green and splice the bnlack and brown?