it really depends on if the macros were made by aliasing the codes in the actual TV device.  if he just dragged raw codes into the macros, then he will have to redo each one of them.

otherwise what Bob said is true, just leave each button in the TV device and drag the new code onto it, then delete the old code.

it would be nice if URC had an automatic code swap feature like Nevo did and I believe RTI does.