You cannot exit the lease, unless you pay the full amount due of your remaining payments... According to BMWFS you signed a ____year contract to keep the car. Unfortunately you're either going to have to buy out the lease (which is a rip off) or buy the car (payout). What you can do is see if any dealer is willing to buy the car from BMWFS (which would in effect fullfill your lease agreement) in exchange that you lease or buy an M3 from them. I did some variation of the above in getting out of my 325i lease.
BTW, there's also leaseswap online but it depends on the terms of your lease as to whether or not it will sell. To be honest if your 330ci has no problems your best bet is staying in it since even if a dealers willing to buy it in agreement that you purchase from them, you still end up losing your downpayment, fees, security, and taxes (if paid upfront).