Brace position? What you lot on about planes for?
Put on handbrake, chock rear wheels, take wheel brace to wheel nuts and loosen, jack up car, undo wheel nuts with brace.
Brace position should be both feet firmly on ground, knees bent and back kept straight. Apply force to wheel brace in an anti-clockwise motion. Nuts should loosen
Repeat with other nuts. Change wheel and apply reverse procedure to above.
Off to bunker again...