Advice for using a high lift jack please?

I am about to change the wheels over on my Defender, but am unsure which point to jack it up at the front end with my High lift jack. Lifted the back of the vehicle up with High Lift no problem, but not sure about the front. With an A-frame fitted, i cannot easily get the jack into where the front bumper meets the chasis. Obviousley i dont want to let it up by the bumper alone, so woundered if i am missing something, or do i need to remove the A frame? Any advice would be greatly appreciated. Thanks guys!!

I always use my Hi-Lift on my standard front bumper with no problems...

you can get a adaptor so you can jack the defenders using the jacking points in the cross member and dumb irons.

hope this helps