Removing the diesel fuel tank from my Avensis saloon

[Handy Andy 11]

Happy new year to all. A few weeks ago my car stopped and after receiving help from this forum I was able to determine the problem being a very dirty fuel filter. I noticed when bleeding the system the fuel was black and dirty, so today I started to remove the diesel fuel tank to clean it out. I have removed the rear seat and the pipes and electrics to the fuel gauge sender on the tank and I screwed off the exhaust and the guard. I also removed the two straps holding on the tank and let the tank drop down onto supports about an inch. I removed the fuel filler and vent pipe. I see two other small black pipes at the fuel filler side of the tank nearest the front of the tank. How can I remove the clips [i.e how to unclip them] to release the pipes and tank without causing any damage to them as it is a cold day here and plastic would be brittle. Any help on how to remove fuel pipes etc. would be greatly appreciated.