Need suggestions for getting old gas out of tank

After 8 years, I'm surprised there would be any liquid in there at all. Do yourself a favor and buy a new tank. Trying to clean out the old one is a time losing exercise in WWIThinking. And replace the entire line to the front as well, cuz even if you manage to clean the tank out, the line will be partially restricted by the continuously evaporating lighter fuels, leaving the syrup behind.So your 5/16 line may be down to 1/4 or 1/8 or who knows what size. So maybe you get it running that way, but the pump may not keep up at heavy loads and so you buy a replacement, and when that one also fails to get the job done, you buy another, thinking the first one was defective.
Or the fresh incoming fuel, solvents the sludge right into your filter, plugging it solid on the way home from a carshow 6 hundred miles from home, or the in-tank sock gets gummed up from the same process.
Or you can just take your chances.......
Keep your AAA card current.
But I gotta tell ya, being stranded on the side of the road,with your son, in 100* heat, is not a pleasant experience. And Lord help you if you took a teenage daughter along. She might not ever let you forget it.
I get the odd sense you are speaking from experience...