How to replace SD card for Nav system?

I'm planning to buy an updated Nav database card for my Prius Prime 2017 Advanced model. It still has the original data card dated May of 2016. McGeorge Toyota says a new one is issued once per year and it will be happening soon. But cannot figure out how to pop open the little door on the lower edge of the 11-inch screen housing. Not sure if it is mechanical such as "press in, pop out" or if it is electrical by having to select some secret menu choices or maybe invisible button choices. Does someone know how to do this?

 

To Mark57, thanks a lot for posting the pictures and info on how to replace the navigation data card. I tried and tried the "search" function on PriusChat to find this info but it never returned anything useful at all. Your good information is buried in the "Prime Audio, Electronics, and Infotainment" forum, then inside an article titled "Navigation Map Version", then within that, it is buried way down on Page 3 out of 4 and each page has about a dozen entries. I don't know if there is some keyword system that could help a user find this easier, but whatever is working now did not lead me to your article.
Thank you for responding and providing a link to your article. Meanwhile, McGeorge Toyota on Jan 30, 2019 tells me that the updated map data cards are still not available though they are overdue from Toyota and they expect them "someday soon".