The bigger bushing worn out easier than the smaller ones on the same control arm.
But changing control bushing, you need have some tools, even a shop press. Or bring to the shop to replace the bushing for you for cost. Consider all the cost, sometimes it makes more sense to buy a new control arm instead.
Check youtube for control arm bushing for your car or at least similar car of the same brand, you will find many detail information.
Just reminder, if you found control arm bushings worned out too much, better double check other suspension parts, especially lower ball joint.
