I spent 30mins trying to get Cortana to pull out information on how to remove apps from my Windows Phone 8.1, a Lumia 1520, but couldn’t find any.
I was trying to remove a Game file from my Collection and when I hold down on the game icon, I’m only given the option to ‘rate and review’.
Eventually, I discovered that I should
1) access ‘Storage Sense’ from Settings.
2) Choose the location of app (in this device, my games are stored in the SD Card)
3) Select ‘apps and games’
4) Select the desired app to be removed
5) Tap on ‘Uninstall’
Hope this helps.