If you don't have a working Mr. Fusion you'll need to generate 1.21 gigawatts of electricity. The only thing that'll generate that much juice is a lightning bolt. You'll also need a way to get a strike, such as a water tower, radio station antenna or a clock tower. Finally you're gonna want a big wire. I'm talking really big. I've made that mistake in the past. Don't do what I did. This resource is pretty useful for working out the math and equations.

You'll want to set the destination time to the date you're interested in traveling to. As long as your unit isn't on the fritz you'll be fine.

Whatever you do, don't visit the old west. It isn't as romantic as you think it is.

Find a long stretch of road and increase speed to exactly 88 miles per hour (141.6 km/h). I've added another speedo that's real easy to read just for this purpose.

If you manage to get power to the flux capacitor and hit 88 you'll be well on your way! Hopefully where you're going you have enough road.

Whatever you do, while in the past or future - avoid this man.