Hi there,
I just swapped the speakers on my 07 C30 last weekend to higher performance Alpine units and the amp can run these without any issues at all.
You will find that the speakers in the doors are riveted in and will need to be drilled out and you will also need to remove the connector plug from the speaker wire in order to wire them up to your new ones.
The speakers need to be mounted on rings in order to fit to the doors and there are plenty for sale on eBay that will do the job.
J
