To change the Primary address to historical, a new address will need to be added to the contact record and made Primary. 
 

Step 1: How to add the new address to a contact record?
 

  1. Go to Contacts > Individuals or Contacts > Organization
  2. Search for the individuals name
  3. Click Manage
  4. Select Profile > Addresses
  5. Click New
  6. Add the new address
  7. Click Save

Step 2: How to make the new address Primary?
 

  1. Mark the checkbox beside the non-Primary address (new address)
  2. Click Primary

Step 3: How to make the old address historical? 
 

  1. Hover over the address you wish to move, and select Edit Address
  2. Under Effective Dates, change the TO date, to a date in the past
  3. Click Save
  4. Click the Historical link at the top to see the old address