Measure the area in which you want to install the counter top. Record both the length and width.
You have several choices for the sink. You can either choose a sink separately, or order a quartz countertop with the sink pre-molded. This type of top is a good idea as you only have the 1 installation to complete.
Quartz countertops are available at at home improvement stores. It all depends on the size of countertop you need. If it it is an unusual size, then you will have to order a custom design.
Move the old countertop once the new unit has arrived. Removing the old top is fairly easy. They usually are installed with bolts under the top which can be loosened, then the grouting around the top can be loosened with a hammer.