Choose Pictures On Facebook Album Cover.

[G2C2C]

I've uploaded around 20 photos onto Facebook as part of an album. Now when on the Facebook it shows 3 of the photos on the page, one large and two smaller, and you can then go into the album to view the rest.

What I'm trying to do is to change 2 of the pictures that are shown on the main page to different ones. I can see an option to change the main picture(album cover) but is there a way to choose specifically the 3 photos on the album cover?

[G2C2C]

When I uploaded the photos they were named by time. Can I change their details now that they have already been uploaded?