"Iíve loosened up the upper and lower spender bolts"
Assume you have the brakes removed down to the bare spindles, right? What I do is pull the cotter pins from the nuts that hold the ball joints to the spindle. Then back the nut off enough to be flush with the threaded end. YOU DO NOT WANT TO REMOVE THEM.
Then use a pickle fork and a BIG 5 pound sledge hammer and put the pickle fork between the spindle and control arm and bang away on the pickle fork (you may have to move the fork around in several positions to get it to break loose). The spring pressure will help to separate the ball joint from the spindle. It will pop on you, but will be held in place because you still have the nuts on the ball joints.
I have a set of torches, so once the ball joints are loose (still have the nuts on them to keep everything together) I cut the springs because I am going to replace them anyway. The other method is to use a spring compressor. You can rent one, BUT, make sure you get the correct one for the older type cars/springs and NOT the compressor for coil overs (guy at the counter did not know the difference and I didn't either and had to return the tool and go to another auto parts store who had the correct one). Compress the spring so no tension is on the control arms. The remove the ball joint nuts completely and you can drop the control arms/spindle down and out. Then remove the spring. Note that the lower control arm has a "pocket" where the end of the spring fits back into when you go to put your springs back in - if using stock type control arms.
I see on some Youtube videos that you can place a jack under the lower control arm and use the weight of the car to hold it compressed and then remove the nut on the ball joint and then drop the lower control arm down to un-compress the spring. Never did this and probably won't either. Might work on a weak or low rated spring. Try that on a heavy-duty/tall spring and you may have a problem. Springs can be dangerous and can injure or kill you. If I don't cut the springs with my torch because I am going to replace them, then I use a spring compressor to safely remove it.
You will need a spring compressor to install the spring as well.
On the idler arm, back the nut off until it is flush with the threaded end and beat on the nut/bolt with the 5 pound sledge. It should pop out. Then undo the nut the rest of the way.