bill of sale

so, I have 4 bikes. 2 Baja DB30s, a Baja warrior and a motovox mbx10. the last 2 I got quite some time ago and the last 2 within the last 2 weeks. I never got any papers with them, they were all secondhand. here in Michigan, to get a 'title' so you can get a trail sticker you need an...