To remove the gasket and replace it you will first have to disconnect the drain and unplug the cord to the garbage disposal. Also, if you have a dishwasher you will have to remove the dishwasher drain hose from the garbage disposal. With the drains and cord removed you can now take hold of the sides of the mounting nut and twist it counter clockwise to unlock the garbage disposal. The disposal should drop straight down.
If you’re like most people who cook, your kitchen probably looks like a disaster zone after preparing a meal for your family and eating it. The cleanup process is going to go much more quickly if you can stuff leftover food waste down the drain. Most garbage disposals have a switch located near the kitchen sink. All that you have to do is turn the faucet’s cold water on, flip the switch, and put the remaining leftovers in the drain.
FYI: I don't believe ISE is using the same quality metal causing these newer models to rust out quicker but, in my recent experience, I found that people who use their disposer properly will get at least 5 years service...that is acceptable for my purposes in the apartments. I did have 2 ISE disposers that only lasted about 2 years. One was from a tenant who almost never used it and allowed it to rust extensively and corrode from non-use. Using it helps keep it clean too. The second one, I determined was not being used properly, i.e., the tenant was not running water before turning on disposer causing food debris to accumulate in the small chamber below the blades/masticator.
Another common cause for a leaking garbage disposal is the disposal flange. A leak at the very most upper area of the garbage disposal could be the garbage disposal flange which goes through the sink. A garbage disposal flange should be sealed with Plumber’s putty and then tightened from underneath the sink. If this is not tight enough or if it has managed to come loose (which can happen) then the garbage disposal will have to be taken down so the flange can be resealed and then the garbage disposal can be rehung.