I just went through this process with a US Towers HDX-589MDPL.
As I interpreted the instructions, I did the following:
Cranked the tower all the way down. (fully nested)
Used the winch fixture to lay the tower over horizontal
*LET IT REST ON A SUPPORT* (railroad ties) near the top of the bottom section
cranked out the tower to access the rotator plate
installed rotator and mast (Tailtwister and 20' 2" chrome-moly)
**RE-NESTED the tower fully.**
Re-raised the tower to vertical with the winch fixture
installed antennas with a "cherry-picker" boom truck.
Using a support and re-nesting the tower before winching it back
vertical meant there was only a little extra torque from the
rotor and mast, not anywhere near as much as if the tower were
still cranked part-way out.
In my reading of the instructions, I believe US Towers says you can
support the tower in a near horizontal position while using block
and tackle to attach antennas, but that seemed pretty awkward to me.
The boom truck (local guy who replaces lights in parking lots)
worked out pretty well.
I have the Mast Raising Fixture in place, but haven't got the faith
it would take to crank the mast up enough to clear the rotator -
that would leave 17' of mast and antennas above the thrust bearing and
3' of mast below - sounds too wobbly to me - does anyone have
experience using this mast raising winch ??
Nick England email@example.com KD4CPL