First, let's see how many moles correspond to 6.30 g of water.
The molar weight of water is 18.01 g/mol, so
[tex]n= \frac{6.30 g}{18.01 g/mol}=0.35 mol [/tex]
Then we know it takes 6.02 kJ to melt 1 mole of ice, so if we have 0.35 mol, the amount of heat needed will be
[tex]Q=6.02 kJ \cdot 0.35 mol=2.10 kJ[/tex]