This used to be quite a difficult one to achieve but it is very easy now.
Install the package Ksuperkey from the AUR if using Arch, start the application by opening the Alt+F2 menu and typing ksuperkey. Now right click on the Kickstarter menu and open "Application Launcher Settings", change the shortcut to Alt+F1 as this is the key ksuperkey uses to open the menu. The application works by activating the key on release so the key is still available as a modifier if pressed with another key.
This needs to be added to the AutoStart list otherwise the application will have to be manually started upon reboot.