Assuming that you are treating the annual lease payments as expense each year: 1. Set up an icon for the piece of equipment. 2. As you make the yearly rental payments use the Other Expense area and choose Rent Expense - Equipment and allocate the cost to the equipment icon. 3. If you buy the equipment at the end of the lease, use the Purchase Option for Equipment Purchase and select the icon and buy it for whatever the final payment is.
If instead you are treating the lease as a capital lease: 1. Before you make your first payment purchase the equipment for the purchase price (your accountant may need to help you get this price) and set up a new loan for the same price. 2. Treat all lease payments as loan payments against this loan.
If you're not sure if your lease is a capital lease or operating/expense lease, talk to your tax preparer. Virtually all of the leases that I've seen are treated as operating/expense leases.