How to repin Motor driver and ethernet shield to work together?

I just ordered an W5100 ethernet shield (W5100 Ethernet shield Arduino uno en mega compatible) and a motor driver (Pololu Dual VNH5019 Motor Driver Shield for Arduino). When I look at the data sheets the Ethernet shield requires ports:
4 10 11 12 13
And the motor controller:
2 4 6 7 8 9 10 12 A0 A1
Now, there are a few conflicting ports:
4 10 12
And I tend to fix it by remapping a few ports.. but I think I'm out of ports? How would I fix my issue?

The schematic connections view I found for the motor controller is this one:

Now I thought about reconnecting (and remapping in the library) the following pins:

REMAP(4)->5
REMAP(10)->3?
REMAP(12)->?????

Now I'm stuck because I don't know if I can connect the PWM thingies to other ports? Anyway, what are my options here?

Okay solved: I used my raspberry PI as an ethernet-to-serial router. no need for the ethernet shield anymore.

In case you're still interested, Mayhew Labs made an 'in between shield' which can be used to re-map the pin connections between shields to resolve conflicts like this. It isn't cheap and adds another layer to the stack, but does make it possible to work around pin conflicts when you want to use standard shields.