If this does not work, locate the white plastic wedges (on both sides), otherwise known as the extension, which forces the contact between the lever and the electromagnet.

Using a tweezer, align the contact points so that the two pieces make are able to make contact.

Also, make sure that the four screws you did not remove from the toaster are screwed into both of the plastic wedges on each side of the toaster (2 screws per wedge). A loose wedge could be the cause of a broken lever.

Once this has been done, plug your toaster back in and check to see if your toaster lever stays down.