Is the truck still fully assembled? You'll need the weight of the engine and body panels to compress the spring enough to safely disassemble the A-arms. Put the front end on jack stands, under the frame, low as possible. Put the jack (a floor jack with good wheels) under the lower A-arm, as far out as possible, 90 degrees to the frame. Compress the spring but don't lift off of the jack stands. loosen one of the ball joint nuts but don't remove. Break loose the balljoint from the spindle. Now see if you can get clearance between the nut and spindle. If not, use a spring compressor to releive some of the tension. Remove nut and slowly lower the jack, allowing ot to roll with the A-arm until the spring is free.
Easy as that,
Scott