Icon sizes and favicon

Hello (doctor who voice), i was wondering how to change the size of the icons, for things such as members or groups?  I have been searching for days but can't seem to find anything.

Next I was wondering how long does it take for the favicon plugin to go into affect when you upload the photo you want display?  

Thank you all for your help.

Beginning Developers

Beginning Developers

This space is for newcomers, who wish to build a new plugin or to customize an existing one to their liking