There is no such thing as a magic drainage method you can for instance take the sender unit out and get your hose pipe in there attached to either your own pump or suck it and hope for the best. Other ways are to take the fuel tank off completely and literary poor it out. You could also get a pipe down the filler hole and syphon it from there if it doesn't have a anti tamper device in the filler neck. Those are basically the ways any garage will do it.
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