1. To change business type, go to Account Settings > Business Information > Update > Edit (First box)
2. Add new guy as user and enable certain functions they can use, go to Account Settings > Manage Users > Update
3. Add their email address and they can log in with same password.
Note: Changing account holder name to another person on the account is generally not allowed and for business accounts, (when company is changing employees/owners) is a rather a time consuming process which could interrupt or delay business operations.
In some cases, it’s better to open a new account and use that instead to reduce/avoid disruption.