OK Dumb question regarding uninstalling libs

[James McDonald]

OK let's say that I had glib-2.0 installed in the default location of 
/usr it's the default mandrake 9.0 rpm install.

Then I go and download the latest src.tar.gz version and ./configure it 
with the defaults and install the new version in /usr/local

How do I un-install the old version in /usr without breaking all the 
dependences and have the apps that where looking in /usr/* for the 
libraries now reference /usr/local....

This is probably an easy answer but I am not sure how linux handles 
version compatibility.

For some reason I prefer to do configure make make install rather than 
use rpm... probably because I learn more.

So the question again is how do you install libraries in different 
locations without breaking dependencies on currently installed apps?

Thanks.