Hi Darryl.
I assume you are outputing a CHM file. Just checking as
people sometimes post in the wrong forum ;-)
Right click on the Map Files folder and import the two map
files. Next double click on the "All Map Files" icon which displays
the Edit MapIds dialog. Select the imported map file in the drop
down at the top of the dialog which displays a list of all the
topic ids added by your developer. What you have to ensure is that
all the topic ids in this list are mapped to a topic in your RH
project. This is done by using the Assign button. RH own help file
does a pretty good job of explaining the process if you get
stuck.