It's possible to do an edit, choose the option from the same drop down menu as the create, just make sure you choose it on the right entry.
I think anyone can edit any entry, but regardless of who does it the entry will need an admin to confirm it before the change shows up. (which is why it's worth at least posting here that you've done it, so I know to go take a look).
Anyway, I've made the tweak to PrimeAgra in the Leca entry.