I've done it with leaving the lower connected. the top will have to be separated. You should be able to seperate them without damaging the ball joint dust boot. You have to unbolt the ball joint and strike the knuckle with a BFH (hammer) the combination of spring load of the tortion bar on the lower arm and the hammer smashing usually pops it right out.

99 Gen 2.5, fixing blown head gasket
89 SWB- 33's, ARB Front locker, SR rear locker/axle, SR F brakes, winch, WST Offroad Armor all Around, 2.85 Aussie T-case Gears (SOLD)
Sold: (2) 95 SR's, 86 SWB, 90LWB, 91 LWB
-Can Change a timing belt in my sleep..