What is the best way to "restart" Zoho CRM?

What is the best way to "restart" Zoho CRM?

We are looking at taking the data we have and restarting our software, essentially from scratch.  We have created new processes within the business and are needing to find the simplest way to export and import data.

Here is the catch:  All of our "Leads" were entered as Accounts and we are wanting to take those "accounts" we have deemed to actually be "Leads" and import them as such.  However, there are fields under Leads that do not have a relative field in Accounts.

Is there a easy way to take an account or a mass number of accounts and "revert" them back to Leads?  Can it be done one-by-one?  Looking for some direction here to make the process as smooth as possible.

Thanks