Tools and materials
New sink, silicone, screwdriver and wrench; hammer, taps, washers and new coupling if necessary; new drain if the old one is to be replaced.

How to remove the old sink
Before buying the new sink you must take into account the size of the old sink and the space available on the kitchen top. If the new sink is of a different size you may have to make new cuts into the top. If the kitchen top is made of agglomerate, PVC or wood it will not be a complicated task. It will be more difficult if the kitchen top is of natural stone, such as marble or granite.
- Close the main water taps.
- Remove the sink that needs replacing.
- Begin working underneath the kitchen top.
- Remove the pressure devices that hold down the sink at the edges. Unscrew the cold and hot water taps and also the drainpipe.

Next: adapting the kitchen top
If you need to adapt the kitchen top to make a larger hole for the new sink, you first need to mark the new measurements on to the space available. 
- Cut through the material. Use a fret saw to cut into the typical plastic, agglomerate or wooden tops.

Finally: installing the new sink
Before installing the new sink, you need to check if the hole for the taps fits the existing water taps. If there is some distance-related problem, you will have to buy longer couplings.
- Extend a slug of silicone along the perimeter of the sink if the new one does not have an in-built waterproofing seal. This will seal the edges and prevent the sink from leaking.
- Place and screw in the fixing devices underneath the kitchen top.
- Tighten until the sink is firmly attached.
- Install the tap in the holes that are usually pre-drilled in the sink.
- Depending on the models and the pieces provided, tighten using a monkey wrench or screwdriver.
- Connect the couplings at both ends: one at the mains and the other at the water tap.
- Finally, install the drain kit (straight tubes, elbow pipes, joints, washers...), adapting to the correct height.
- To do this you will need nothing more than your bare hands, as they tighten easily.
- Now open the mains and hot and cold water taps and ensure there are no leaks.