Web Design Architecture2 template change background pics

Hi, I am at a loss, I cannot see how to change the two small pics at the bottom of the Architecture2 template.
I thought it was going to be simple but it isn't, (or maybe its me thats simple).
The pics show as pic_2 & pic_3 and I have changed them to what I need but no good the originals still show, even after repeatedly saving and swearing at them. And yes they are in the correct folder.
Pic_1 shows as a true pic in the code and I have changed that one OK.
Can any one help please.
quintain

 

seen how to do it; simple when you take the time to read the code