Splitting a large RM8 file into two smaller files

Is it possible to take a RM8 file and split it into two separate files? Specifically, I would like to have my family in one file and my wife’s family in a separate file.

It’s not normal to split like that, probably you may make of one of the parts and then move to another new three.

create 2 new empty trees. Then drag your half to one and your spouse’s to the other.