Opel ASTRA Owner's Manual page 232

230 Vehicle care
4. Set the jack to the necessary
height. Position it directly below
the jacking point in a manner that
prevents it from slipping.
Ensure that the edge of the body
fits into the notch of the jack.
Attach wheel wrench and with the
jack correctly aligned rotate wheel
wrench until wheel is clear of the
ground.
5. Unscrew the wheel nuts.
6. Change the wheel. Spare wheel
3 231.
7. Screw on the wheel nuts.
8. Lower the vehicle and remove
jack.
9. Install the wheel wrench ensuring
that it locates securely and tighten
each nut in a crosswise
sequence. Tightening torque is
140 Nm.
10. Align the valve hole in the wheel
cover with the tyre valve before
installing.
Install wheel nut caps.
11. Stow the replaced wheel 3 231
and the vehicle tools 3 218.
12. Check the tyre pressure of the
installed tyre and the wheel nut
torque as soon as possible.
Have the defective tyre renewed or
repaired as soon as possible.