How much force is required to move 6585 kg the following distance: 792
m horizontally (by truck), and 30 m vertically?

Horizontal force will depend on the friction involved.  Ideally, zero
should be enough if you had infinite time to move it.

Vertically, assuming we are talking about within the Earth's
gravitational influence:
The load weighs 9.81 x 6585 N = about 6.4 x 10^4 N.  That is the force
that will be needed to balance gravity.  To raise it 30 m or 3000 m
requires no additional force, just energy.

As an example, to raise it 30 m will require 6.4 x 10^4 x 30 Nm = 1.9 x 10^6 J.

tss, tss Xargi,

 Force for vertical pull is also arbitrarily low, if you have time,
using a device known as pulley.
http://en.wikipedia.org/wiki/Pulley

Asker needs  no number, s/he just needs to read on definition of force
http://en.wikipedia.org/wiki/Force

D'oh!
Now, if only we had a sky hook to hang our pulley on!

Now hang on just a minute there, hedgie.
Sure, you can use mechanical advantage to multiply force so that the
applied force can be lowered arbitrarily, but that does not detract
from the requirement that the force acting on the object must
compensate for gravity.  Unless 6.4 x 10^4 N is applied to oppose
gravity, that load is not going to go up.  That you may be using a
lever a mile long with an ant on the end is irrelevant; 6.4 x 10^4 N
must be generated at the other end.