Bill of sale with mobile home

[Eric Wallet]

I am in the process of purchasing a mobile home from an individual who still has a mortgage on the home and have a few questions about the transition purchase process. 

I will be executing a bill of sale, sellers disclosure and an Application for Statement of Ownership once I receive verification of the amount that is due. After signing both the bill of sale and Application for Statement of Ownership documents by both parties I will pay off the amount directly to the mortgage company while also requesting a Release of Lein. Once all paperwork is gathered I will mail off to the Department of Housing and Community Affairs to acquire the new ownership paperwork. 

Do these steps sound correct? 

Do I need to have both parties notarize the bill of sale or the Statement of Ownership? Also do both parties need to be present at the notary?