To simplify the expression \(-\frac{1}{2}(-6x + 3)\), we can distribute \(-\frac{1}{2}\) to both terms inside the parentheses:
\[ -\frac{1}{2}(-6x) + \left(-\frac{1}{2}(3)\right) \]
Calculating each term:
- \(-\frac{1}{2}(-6x) = 3x\)
- \(-\frac{1}{2}(3) = -\frac{3}{2}\)
Putting it all together, we have:
\[ 3x - \frac{3}{2} \]
Thus, the simplified expression is:
\[ \boxed{3x - \frac{3}{2}} \]