Removing the Network Manager
 

I am running Ubuntu 12.04, and the network manager is giving me headaches largely because it does not support dial-up connections. Has anyone tried to remove the network manager and install a 3rd party network manager or manually configure the network connections? What would be the safest way to go about this?

Have you looked at Ubuntu's information about dial-up:

https://help.ubuntu.com/community/DialupModemHowto

Dial-up and TCP are two different things. I doubt you have to remove network manager to accomplish dial-up.

I have accomplished dial-up. That is not the problem. The problem is that the system through the network manager doesn't recognize the dial-up connection as a network connection. Hence, the software center won't all installation of software and the update manager doesn't work properly. Also, other programs such as Evolution won't work because they think they are offline. Only browsers work.