For the purpose of changing wheels, Datsun 1200s were equipped with an easy-to-use scissor-type Jack. It shipped in the boot, as shown in the Owners' manual.
USA 1972 Owners manual (see page 27 for details):
First apply the parking brakes...
Jack-up the 1200 at these points:
Using OEM jack (see Owners Manual above):
- under rocker panel front
- under rocker panel rear
Be sure to use an old-school Nissan or Toyota jack with a "slot" to fit over the rocker panel seam.
To remove the lugnuts, you may stand on the wheel wrench. But don't stand on it to tighten -- they should not be tightened too much to avoid breaking the lugs or warping the brakes. Only tighten the lugnuts using your hands on the wrench.
NOTE: Tighten in the pattern shown in the Owner's manual
Remove by turning anti-clockwise. Tighten clockwise. Remember: "Righty-tighty, lefty-loosey".
CAUTION: Don't be tempted to stick your head under the car, unless you fit jackstands (safety stands) to the car first.