Changing default instrument?

I have the Grand Piano instrument from SamplerBox.org on a thumbdrive that I have plugged into my Pi.

Is there a way to make this the default instrument that loads on startup without having to mess with the /samples/ partition?

The + and - buttons on my M-Audio Oxygen 61 keyboard do not change instruments, so I am currently just stuck with the default saw synth.

Thank you.

Hi,
I just plugin the thumb before poweron. Then SB picks that as default.