Can-bus shield

Hello everybody and thanks for any help....
my idea is to read to a single arduino, on which there are two stacked can bus shield, two separate messages sent respectively by two different microcontrollers arduino that have on each a can bus shield...how can i do??? I'm new with this sort of communication....
Thanks a lot!!!!
GM

That may be a bit difficult to use two on the same Arduino. The shield uses the SPI bus for communication with the Arduino, and D10 as the CAN SPI slave select. You would need to change one of those shields to use a different pin for the CAN bus slave select.