Mobile
On the side menu select the Farm settings icon.
Tap inputs, here you can manage your inputs.
Tap the three dots on the right of the input and then select "Edit" or "Archive" as desired.
You can view archived inputs on the manage inputs screen. You can also unarchive the input.
Web
Go to Farm settings (cog on the top right) and select the Inputs tab.
Here you can select to Edit or Archive inputs as desired.
You can scroll down to view archived inputs on a list. If required you can also unarchive the input.