Think first about the landlord's position. The landlord's priority is generally to ensure that he has a reliable tenant. Often the crucial factor is whether you can find a high quality tenant to whom you can assign the lease (or who will take a new lease if your lease is terminated).
Try to find out any other details about the landlord's position which will help you negotiate. For example, if the landlord has cashflow problems, he may be happy to negotiate for an immediate cash payment in place of future rental income.
Make it clear to the landlord what risks he faces if you cannot get out of the lease. For example, if you are in financial difficulties, let the landlord know: he may prefer a negotiated agreement to the risk of seeing your business fail and default on the rent.
Plan your negotiating strategy carefully. Think about what concessions you can make and which you would prefer. For example, it may be preferable to pay a cash sum for a clean break rather than guaranteeing future payments.
Finally, use your - or your adviser's - negotiating skills. Don't give your position away. If the landlord knows you are desperate to get out of the lease, he will be in a stronger position.
