Most upgrading systems use channels, but there’s actually an easier way that uses just wires!
Step 1: Make a vending machine and set it to the item you want.
Step 2: Make an item granter, set what item you want to get rid of.
Step 3: Set the amount to -1 so the item will get taken away.
Step 4 (Final step): Connect it with a wire and set it to this configuration.
And you’re done!