First i laid out towels all around the tank to keep the floor clean/dry.
I shut off all my pumps/heaters.
Drained the water to about half and used the water to fill two rubbermaids.
Then i started taking all the driftwood and rocks out which i put into plastic bags.
Took one heater and placed it into one of the rubbermaids.
Drained the tank down to 1/4.
Removed plants and placed them in rubbermaid.
Caught the fish and placed them into the heated rubbermaid and put the lid on, also put a digital thermometer in to periodically check the temp.
Used my largest net to scoop as much gravel as i could each time, supporting the bottom of the net with my hand to prevent it breaking.
Dumped the net into doubled up kitchen garbage bags on the floor right next to me.
I managed to get 98% of it out. After that i put the new sand it, driftwood back in, plants back in, refilled with water, put the water from the rubbermaids back in, turned everything back on and let the filters deal with the cloudyness for an hour. Then i put the fish back in!
Took about 2 and a half hours and that was on my 75 gallon.