If you are hoping for some magical way to increase your 1/2 ton Suburban's towing capacity... there isn't one. When you compare to 3/4 ton truck or SUV options, they have a bigger and heavier duty engine, transmission, suspension, brakes, and tires. Don't forget about the weight of passengers and other gear in the Suburban, as those items are being "towed" and take away from the cargo capacity also.
If you are towing short trips on flat ground and in nice weather, you may never notice the towing limit. But add in any hills/mountains, traffic, long driving day, or windy conditions, and that trailer size has a good chance of constantly reminding you that it's back there ("tail wagging the dog" we say here sometimes). You didn't mention the trailer length, but with that weight I'm guessing it's around 30' which can be dicey for a 1/2 ton vehicle. Can that towing be done? Probably. Will you enjoy it? Doubtful.