First thing to do is to put your bench tops in place, but don't fix them down yet. Leave them loose; you may need to move them when cutting the holes to avoid cutting anything below.
Most sinks and cook tops come with a template to mark the size of the hole needed. If you didn't get a template then place your sink or cook top upside down in the desired location and mark a pencil line around it.
If your sink bowl is going to interfere with the cabinet sides you may need to mark and cut out the section with a jigsaw.
Make a second line within the first line you marked on the bench by about 10mm. This will be your cut line. Hint - place masking tape where the cut line will be to stop the jigsaw from marking your tops.
Next drill holes in each corner. It is important to make sure the corners are rounded; if you have 90 degree corners the laminate may split and run! Use a drill bit that has a larger diameter than your jigsaw blade.
You can now use your jigsaw to cut along the cut line from hole to hole. Using a brand new fine blade in your jigsaw will make the job easier and giver a better cut. Don't worry if the cut is a bit jagged or not perfectly straight as the lip of the sink or cook top will cover that. When cutting let the jigsaw do the work. Don't force it along or try to rush.
Always wear appropriate safety equipment when working with power tools.
Make sure you check for clearances underneath where you are cutting! If the cabinet or something below is interfering then move the top to a clear area. That's why we don't fasten the tops down first.
Don't forget to support the cut out piece of bench when you are nearing your final cut! If you are supporting the underneath with your hands make sure you know where your fingers are before cutting!
Tighten up the bench top toggles supplied.
If the toggles interfere with the railing of the cabinets you will need to cut a notch to give you clearance to tighten the toggles.
You can now install your sink. Before you put the sink in place run a small bead of silicon along the edge of the hole. This will give it a water tight seal. Hint - Don't tighten your sink clips too much or they may break or pull away from the sink.