It 's easy to change RealTrack instruments on any of the 24 mixer channels. There are several methods.
1. Open Bar Settings and select the Chorus and bar number and track you want to change RT instruments on.
2. In the upper middle area of the Bar Settings Window, select the button labeled RealTracks. A list of all the RealTracks on your system will be available to select a replacement instrument for the current RealTrack instrument on that Mixer Channel.
3. Repeat step two to return to the original RealTrack instrument or select a different RealTrack instrument.

There's also a very powerful arrangement feature for RealTracks called the RealTrack Medley Maker. It's accessed from the RealTracks Picker.
The RealTracks Medley Maker is a 10 track sub-mixer that's available for each of the 24 mixer tracks. Every track in the mixer can have as many as 10 instruments assigned to each track and programmed to play either simultaneously or consecutively in multiple configurations. Instruments can be volume adjusted and panned and and instruments can be used multiple times in the sub-mixer.

You can review the RT Medley Maker in action by searching and selecting a Medley from the RealTracks Picker.

Attached Files (Click to download or enlarge) (Only available when you are logged in)
Bar Settings Window and RealTrack Button.jpg (53.22 KB, 59 downloads)
RealTracks Medley Maker.jpg (138.19 KB, 59 downloads)
BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.