Any tips on installing a fuel level sensor assembly in a tight space?

You’ll have over 600 lbs of fuel in that tank.
Is your middle name Hulk?

 

Just seen your post, yeah don't take the straps right off since it doesn't look like the J-brackets cradle the bottom of the tank.

 

I typically pump out the tank and put a floor jack and block of wood under the tank to support its empty weight. Then slack off the straps enough to turn the tank. I would leave the straps on for safety. Obviously don't put yourself in a position where you could get pinched. Change your sensor, rotate the tank back and torque down the straps.

 

Not until you get some weight out of the tank.
So you got rid of other tank?

 

I would close it up and take a load somewhere and burn some fuel.

Make sure you don't run out but try to come back with as little left as you can and then you'll have to siphon it into something. Some tanks have a drain plug on the very bottom of them.

Then do like a model said. You may have to remove those back fuel lines to be able to rotate far enough.