[header] How to melt velveeta cheese [title] Cube the cheese. [step] Use a sharp kitchen knife to cut the velveeta cheese into 1/2-inch to 1-inch (1.25 to 2.5 cm) cubes. [substeps] Smaller cubes will melt quicker and more evenly than larger cubes. 
Regardless of what size exactly you make the cubes, try to make sure that all the cubes are roughly the same size. Cubes that are unevenly sized will melt at different rates, and as a result, some of the cheese may burn before the rest melts down.