If the recording was over-driven there's little to be done but reduce volume. VP inputs the file without altering sound, unless you change it.
Click the FX button at the bottom-left of the sound track, then click the large green + at the upper-left of the effects window.
Choose either AMPLIFY or NORMALIZE, and move the slider to the left to reduce volume.
If no joy, please upload a sample, per c_major's suggestion. Be sure to make it public, and post the link here.