Refer to my previous post.
I gave pretty step by step there.
In the Launcher properties inside of main menu editor for install Updates.
Hit New Item.
Empty box for name type in: Install Updates
Empty box for Command type in: x-terminal-emulator --geometry=95x25 -t "Linux Lite Updates" -e /usr/scripts/updates
Empty Box for Comment type in: Get the latest updates for your computer
Hit OK and save it.
Hit New Item again.
Name= Help Manual
Command = xdg-open /usr/share/doc/litemanual/index.html
Comment = The Linux Lite Help & Support Manual
Hit Ok to save it.
Hit New Item again
Name= Install/Remove Software
Command = synaptic-pkexec
Comment = Install, remove and upgrade software packages
Click OK to save it.