How do I calculate this?

After getting her degree in marketing and working for 5 years for a large department store, Sally started her own specialty shop in a regional mall. Sally's current lease calls for payments of $1,500 at the end of each month for the next 60 months (the next payment is due in 1 month from today). Now the landlord offers Sally a new 5-year lease which calls for zero rent for 6 months, then rental payments of $1,575 end of each month for the next 54 months. Sally's required rate of return is 10 percent. By what absolute dollar amount did accepting the new lease change Sally's theoretical net worth?

The answer is $5,650.48 but I need to know how to find the answer