How do i change my 47cc pocket bike into electric (keys) start and what do i buy?

How do i change my 47cc pocket bike into electric start???

47cc Pocket Bikes Make your Ride as Thrilling as Can be

What are pocket bikes?

Pocket bikes or mini motos are small, speedy, gas powered motorcycles about 47 inches long and 18 inches tall. The smaller models reach a speed up to 35 mph while the superior models can achieve up to 50 mph. Earlier, pocket bikes were specially made and were costly but with these becoming [...]