Collecting Security Deposit from Existing Tenant

[Tammy Mason]

How do you collect a security deposit for tenants that currently live in one unit of a multi-family I'm scheduled to close on in two weeks? The seller never collected a security deposit from the tenants and has indicated in our contract it is my responsibility to collect the security deposit.
How would you go about collecting the deposit? The rent is currently $1K (which is slightly below market value).