How to remove manually-installed plasma widgets

Since it was hard form me to find this on the net, I thought that was worth to spread the knowledge.

I did only the 50% I missed the .desktop file in ~/.kde4/share/kde4/services/

To remove non working widgets in the widget list, remove the related desktop files in:

~/.kde4/share/kde4/services/ (Desktop File)
~/.kde4/share/apps/plasma/plasmoids/ (Widget Package)