Nope the spring will not break them loose.You dont even need to undo the upper.Just remove shock.Floor jack under lower arm.Undo the lower nut and leave it on a few threads.Then just smakc the knuckle and it should pop.When it does undo the nut and slowly lower the jack.Make sure the front end sits high on jack stands.As the lower arm comes down so will the spring.To asseble just inatsll the new spring and jack up the lower arm.You might have to push down on the upper at the same time to get enough threads to start the nut.Tightn install cotter pin and shock and you are done.My last one on my kids truck one lower were stuck so a pickle fork was needed.The other side popped easy with a few hits on the knuckle.We did all the ball joints while it was apart.Rocky