Gary, there are a couple of ways you can do this. It really depends on how many individuals you wish to move. The easiest way to move a bunch of them would be to create a GEDCOM of that line and IMPORT it, if you know they are all related to the other line. You can select which group you need by creating a focus list for them (refer to your HELP file for Focus Lists).
The second way, if you only have a handful of individuals, would be to open up both databases in a split-screen view. Then just copy the data from one to the other by typing in the relevant entries. You can use "copy and paste".