The first step you will need to do is finding the linux source code for your device drivers and then figure out where in the either NanoBoot or Synology Kernel source code to add the Device Driver source code. Then the links below will help guide you through the rest of the process (although I can't say that I've successfully installed the drivers yet):
http://hallard.me/how-to-install-kernel … 0-dsm-4-1/
http://www.tyan.com/manuals/LinuxUSB3Dr … Manual.pdf
I am trying to use the NanoBoot Kernel source first, since it seems to make more sense and I'm not sure I will be able to remove and then re-install the USB Driver Module while I have XPEnology running from a USB Stick. So I might have to create my own Boot Image in order to get the updated USB Drivers integrated into XPEnology.
Update: I've successfully compiled and installed the drivers I needed. But I had to use the Synology Kernel source code. how-to-add-drivers-trying-to-compile-tbs-pci-card-driver