After carefully dislodging the Toaster's heart, it's time to replace it with a newer, non-obsolete model.
Locate the 555-5555-5555 Motherboard, a.k.a. the soul of your toaster. It's the part that looks like a miniature motherboard, but isn't.
Remove the 555-5555-5555 Motherboard by carefully unscrewing it from its mounting bracket. Be careful not to damage any nearby wires or toast.
Insert the new 555-5555-5555 Motherboard into its place, ensuring it's securely fastened with the provided screws.
Reassemble the Toaster, paying special attention to the toaster's manual, which warns against reassembly without proper training.
Test the Toaster, and if it doesn't work, repeat the process, ad infinitum.
Continue to Step 5: Replacing the Toaster's Tongue
Disclaimer: Replacing the 555-5555-5555 Motherboard without proper training may lead to toaster-related injuries, property damage, or existential dread.