Heres what ya do man.
1. Right Click the desired track
2. Scroll down to "
Envelopes"
3. Then "
Create track envelope"
4. Then "
Volume"
Then a little blue bar will appear above the middle of the track. If you scroll your mouse across it, it will show the volume it is set at. To change the volume at designated parts of the song, put the cursor on the volume line (at the point you want the volume to increase/decrease) and double click. A little blue box will appear. Go to the next point where the tracks volume goes back to original volume, and repeat. You are going to want a blue box at the start and finish of desired part of the song. Now click in between the blue boxes (on the volume line) ONE time and HOLD the left mouse button, you can now drag the volume up or down. The really cool thing is you can do this as many times as you want. You can kill the track completely or crank it (Good for drum fills, guitar solos, etc.). You will need to play with the little blue boxes for a little while to get used to it, and dont worry about screwin up cuz you can go right back to where you were by holdin Ctrl and pressing Z. If you have any more questions let me know. Hope this is what you were looking for.