I think NMSROOT/bin/uninstall.sh will prompt you to choose which components (HUM, RME, etc.) to uninstall, depending on what you have installed. E.g.:
1) CiscoView 6.1.8
2) CiscoWorks Assistant 1.1
3) CiscoWorks Common Services 3.2
4) Campus Manager 5.1.3
5) Internetwork Performance Monitor 4.1
6) LMS Portal 1.1
7) Resource Manager Essentials 4.2
8) All of the above
Or, you could simply unregister HUM from Common Services - Server - Home Page Admin - Application Registration, to get it out of the way on the browser GUI.