I have a burned out blower for a spa that is located more the 50 feet
from the spa. The blower was 1.0hp and 220v (USA). The replacement
blower I have is 110v, and 2.0hp.

The wire from the old installation is as follows:

From a sub panel, located on the opposite side of the house, there are
three breakers. One set on the left provide 110v for the in water pool
light, and the pool pump. The right side has the double joined 220v
breaker pair for the 11k spa heater and 220v for the previous blower.

The wires at the blower end are red black and green. There is also a
heavy gauage green wire that runs from a pole in the ground, along
side the air feeder tube, that runs some 75 feet to the spa, located
on the other side of the pool, from the side of the house. The green
wire was previously connected to the metal housing bell that covers
the blower blades. The entire housing of the previos blower was metal.

The new blower is plastic and has three wires: black, white and green.
There is no obvious outside lug in which to connect the old earth
ground, connect to the pole.

My question is, can I use the red wire as a neutral by moving it in
the sub-panel to the neutral bus, making both ends with white tape.
Then connecting the black wire, to the black wire on the blower, the
red wire (Now connected to the bus) to the white wire of the blower,
and then the green wire to both the pole driven in the ground (If
nessesary) and to the ground that returns to the breaker.

Im assuming its a complete no in attaching the white wire to the
grounded green wire (One connected to the pole in the ground next to
the blower), the black wire to the black from the sub-panel and the
green to the green from the subpanel, (Sounds like this is trouble).

Or should I go through the pain of running a white wire through all
the conduit?

Bottom line, Im selling the house and the pool and so Im not conserned
with 110v vs 220 which one is better and so on, let the new owner
worry about efficiency, they should be happy Im putting in a new
blower vs. the dead rusted one. I just dont want to electricute
anyone. We can also skip the call an electrician as thats an obvious
solution, but with the existing wires in place and a smiple matter of
moving a wire in the sub-panel (After shutting down the main) seems
logical, easy and safe? Any suggestions, background, reasons, Code
answers would be much apreciated.

Thank You

Pete