Inside the tank are two bolts holding the tank on to the base. Unscrew these two bolts and carefully lift garbage disposal the tank from the base. Remove tank to the trash.
When you get to the house stand if front of the toilet and locate the water shut off valve. Should be down below the toilet on the wall. Just turn it off (righty-tighty) completely and flush the toilet. All the water should have left the tank, well at least most of it. If there is remaining water line repair get it out with paper towels or a rag. The important thing is that no more water came in. If it did then your valve is not shut all the way or not working and you need additional help.
A c clamp or hose clamp is use full for securing or holding the rubber used to seal leaks on piping. However, a clamp should be used carefully considering the type of pipe being repaired, clamping too tight will fracture the pie leaving you with a bigger problem than you started off with.
OR, you can think about developing a group, where relationships prevail, your time and efforts come with great rewards, and you can multiply your efforts through helping others succeed, as they help you with introductions and referrals. So with much less time and effort, you can benefit from creating your own referral group.
Be certain that the bathroom exhaust fan vents to the outdoors, not into the house or attic. If the exterior vent dampers don't operate properly or water line repair don't seat well have them fixed or replaced.
People who own rental properties are great ones to give you information. With all of the service people needed for maintenance on their units, they typically know who to call and what level of work they perform. Most property owners will be more than happy to give you the information you seek. In fact, they were probably in your shoes at one time.
Over the counter drain cleaning products offer convenience and effective results. However, they are best left to those who need to simply improve the flow of water, not those who need to repair it.