First you have to get all the rockets in the first part of the
level. Then take the tank and blow up the tank shooting at you,
just after the first barricade.  If you look just off to the
right there is a pass that will bring you to the closest tank.
Look to the right and blow up that tank too.  First tank,
throw a smoke grenade then run up plant the C-4 and run!  Do
the same thing for the second one parallel to the first.  If
you look directly after the second non-blocked tank there is a
pass that ends at the cliff.  Destroy the tank and the guy. 
Turn around and go left down the road.  BE CAREFUL!!!  A
tank is waiting for you around the corner.  Destroy that tank
with yours then move on.  The rest of the level shouldn't
give you much trouble.  Good Luck!!!!