Open the tube and place one hand on it and with the other hand hold the end of either side and slowly pull it off.
This is the most important part and it involves removing whatever glue might be on the edge. Rubbing down the edges with any paper towel. Cloth, or sponge with a little soap and water should remove it. For heavier glue wet with rubbing alcohol or use a very light grade of steel wool but in most cases the first washing should clean the surface properly.
Dry the edges totally. Very important!
When I send gaskets, I fold over the edge on the right side of the gasket so you have a starting piece of paper to pull from the rubber gasket.
Start slowly first by pulling the paper a few inches off and placing the end of the gasket at the end of the tube. Then slowly pull up the paper up to the first hole position and line it up over the hole and lightly press it down.
Again pull off more paper and bring the gasket up to the second hole and again line it up and press and finally do the same with the third hole-You can pull to stretch the rubber gently if you need to insure the holes are fully open.
From there continue to pull the paper and following the edge place the gasket down and bring it next to the hinge and down to the bottom of the tube. Again, if you need to pull it down a little to reach the edge it is ok but not too much force.
Close the tube and secure the nuts and bolts but not too tight -You have just replaced your gasket.