Without Ubuntu Software Center in Lubuntu I was unable to edit opening apt links in any program in Firefox (see this question). After installing Ubuntu Software Center, that problem is solved, but could I use another program instead of Ubuntu Software Center for the same purpose? I find it too heavy, and to install I prefer the Terminal, gdebi, Lubuntu Software Center or the Synaptic.
(Now that I have the apt option in Firefox/Preferences/Applications, I try to change Ubuntu Software Center to Lubuntu Software Center but this does not change the option.)