Yamaha DTXpress/DTXplorer/DTXtreme

Hi, 1st post here...

I was wondering, is there a way to add new & better drum samples to 
the DTXpress kit's brain?
The brain has 16 bit samples, is that all I can get even if I can 
add more sounds?

I was checking out some of those drum CD sampler's which have much 
better sounding drum samples & higher sample rates.
Is it possible to load these new samples into the DTX's brain?
Or is it possible to utilize these samples with my DTXpress kit at 
all?

I was hoping that at least, I can record midi into my Cubase VST 
program using my DTX's kit, then have these CD drum sample with much 
better drum samples play back instead of my own kit's sounds? This 
is possible correct?

Are there any other options here that I'm missing to get my DTX kit 
to add/play more sounds & better drum sample sounds?

Thanks, Steve