Don't think you can empty it by removing the fuel filter as I'm sure the fuel pump needs to be running, and therefore I think the engine too to keep the pump going but not 100%, so it may not drain out as your engine would stop running....lol.
An alternative would be to connect a bit of hose to your fuel rail on the shrader valve (basically the same as a tyre valve) on the front of the engine and just let your engine run on tickover, the fuel should keep coming out of the valve until the tank was more or less empty and then the engine would just shut off obviously. Again, this might not need the engine running as the pump usually primes itself before you start the car so may just keep spinning away freely in which case you could try the fuel filter method. I should have tried the fuel rail one myself by now so could've told you about the pump running or not as I'm upgrading the performance on mine and need to check the flow but as my cars been a little funny I've not had the inclination to do it.
A decent motorfactors or even Halfords should have a connector for this I'd have thought. It's a bit of chew I know but it's got to be better than removing the tank itself although if it was me I'd probably have a go at the old sucking method first....lol.