Hi,
Here is a link to an ifixit answer that details how to remove/replace the card cover,
[post|61762]
The part in the link in the Chosen answer is no longer available, but here is a link to another supplier.
https://www.uscamera.com/vk4684.htm
If this doesn't suit you just search for Olympu Evolt E510 card cocer for results for other suppliers.