In theory, all you need to do to remove a shower tap is disassemble it and install new parts when necessary - but it's not that simple.
There are many different types of taps, but the most common one is some kind of a knob or lever system. You will need the following parts before you fix a tap.
Tap valve.
O rings.
Tap spindle.
Tap washer.
New handle.
The most common problem is corrosion or calcium build-up on the part that you have to turn. This, in its turn, triggers a release mechanism and makes the tap unusable. You have to remove shower taps that are stuck like this, but before doing so, check all connections first. Make sure they are not corroded and don't use forced methods to unclog the system.
To remove any tap, you have to turn off the water supply from the mains of the home. The mains handle should be turned to restrict the water supply to the tap. Merely turning off the mains in the home will eliminate supply of water. Once the mains are off, open all the taps to drain the water filled in the pipes. If the problem tap is in the shower, check the waterproofing around the tiles.Body washers can be disassembled by removing the screw. It's easy to remove a body washer. Check the tap valve, for any defects. Ensure that the O ring and flange are okay. The O ring usually breaks down. Check the tap seat on the wall for any defects. You might end up changing the tap washer if the tap washer has any issues. Many people face difficulty in removing the spindle, handle, tap washers, screws, nuts, button (button is very tricky), etc. That's because the spindle is hard to reach. A spindle is basically the core. Also, ensure that the hot water isn't running in the tap. The washer is pretty easy to reach. Most people are able to change the washer without much effort.
Most modern taps are easy to disassemble and use everyday tools to repair or replace their parts. However, older models require more attention and patience because they can be stubborn and it's easy to damage them accidentally. Some models are equipped with a cartridge, which is an easier system to replace. You just have to remove old parts, insert new ones and you're done. If this is not the case, you need to buy new parts or at least know what kind of part broke down and how it should look like when in its original form.
The first thing you should do before changing a tap is to turn off the water supply for your entire home. This will lower the amount of damage if something goes wrong during the installation. Once that's done, gather all equipment necessary such as pliers, screwdrivers, pipes and tape. Make sure everything is close by because you may need them right away.
Without tools it's impossible to remove the tap, so make sure you have some on hand before you start the project. Read the instructions and steps for your new taps and understand how they are assembled if that's not clear from their appearance. You might as well install a new showerhead to suit your new taps.You'll need a spanner, shifter, (though shifter isn't so important) cap, thread and washers.
Removing a tap mixer is relatively easy, but you have to follow the instructions for your specific model because they are not all made the same way. The most important thing you should keep in mind is that some models use a cartridge and others have separate connections and parts that need to be removed, replaced or repaired first if necessary.
Disassembling the whole unit.
Removing the plate over the release mechanism with a screwdriver.
Pulling out anything that's stuck with pliers.
Installing new parts.
That depends on the type of your shower tap. Some models have a cover located in front of the handle or knob, while some others don't have that feature at all. To remove a shower tap without a cover, you should just unscrew them and take them off with care because they can be glued to the rest of the unit (usually if there is no cartridge). This will expose the release mechanism and you'll be able to remove it. Removing a cover is generally easier than removing a shower tap. The only problems that may arise are with models that have plastic or rubber parts that can get damaged when disassembled.
This is another point in the installation process where things may go wrong if you're not careful enough. To remove a shower tap you have to separate the head from the pipe it's installed on (the pipe connects the tap and a water source). This can cause flooding or damage to small components attached around that area. Once the head is removed, you can access the rest of the components inside. There are many ways to remove a shower tap and it usually depends on their model:
On some models, the pipe can be unscrewed from its base. This way you won't have to touch the tap itself or any moving parts connected to it.
You may have to use a wrench (usually adjustable) if there is no empty space for your hands around the area. It's best not to twist hard.