Can I repair back multi controller only?

My Canon is in fine condition but just rear multi controller doesnt work properly. I need know if there is any way to repair only multi controller, not to change whole back cover.

Can you send me ID of spare part (multi controller) if it is possible, or ID of whole back cover.

And if you know good internet shop with shipment to Europe and send me link, I will be very pleasure.

Thank you in advance

PS: Sorry for my bad English