Since the last change, deleting friends is slightly different.
1. Click on the Milhouse/Bart icon on the bottom right of your Springfield.
2. You will now see all of your friends' Springfields. Click on the Milhouse/Bart icon again in the lower right hand corner of the screen.
3. You will see a black box with four icons on the top. Click on the fourth one (it's the orange origin symbol)
4. You will now have a list of all of your friends in alphabetical order. Scroll up to the one you want to delete and click on the image on the left (not the hide button).
5. Click "unfriend in origin" at the bottom of the new pop-up.
6. Click the red "yes".
Your friend is history.
BTW - if a friend is non-responsive for a short period of time - don't be in a rush to unfriend him/her. They might not play for a few days and they'll be active once again. (I had some friends that were totally non-responsive during the entire Valentine's day sequence and became active again as soon as it was over.)
Hope that this helps.
Well considering many people are having friend issues, it was probably removed from the app so they can troubleshoot. Try the Origin desktop app. I think you can still delete from there.
In the game you go to visit your friends (Tap on the milhouse icon)
On the bottom left you will have the origin sybol - click on it. Click on the link for "Friends" you can then click on the friends you want to delete.
Hope this helps
donwload and install origin in this link http://www.origin.com/mx/download then open origin a choose friends, this show the list of your friends and the last time they conected, very useful to know who delete and who add, in the iphone i can't do that, i make this in my pc