"If, for any reasons, the install will fail, or if you are on a Windows system, you can do all this manually. Copy the .inx and .py files from the modules folder inside the inkscape extensions directory, then edit the keys/defaults.xml (on Ubuntu this folder is located in /usr/share/inkscape folder) and add the content of the keys.xml folder. That's it. Restart the inkscape and you're done." Can I get a step by step for this? I can't make sense out of this.