Looks like you ordered the right pads to me. I've yet to change pads on my 230, but I've done a few others. Try opening the bleder while compressing the caliper piston. A small amount of brake fluid will be lost but can be refilled after the job is done. This should get you the room needed to get the pads in and over the disk. The piston should go almost flush with the caliper body. Becareful not to compress it too far or it may slip past the top piston seal.