Place the newly bent paperclip onto plastic lever weaving it through the divots. Make sure that when the main spring comes down it engages the paperclip to push the lever down.

Use an adhesive to bond the paperclip to the plastic lever. A plastic welding adhesive such as JB weld will work best but super glue or even a hot glue gun will work as well. As long as the paperclip stays glued on, the toaster will function fine. Make sure to fully cover the paperclip with the adhesive.