Hi there.I have changed loads of laguna lower arms and they can be a little awkward the first time.You are supposed to remove the complete subframe assembly to change them as the wishbone mounting bolts come out upwards and snag on the body. I have done them without doing this by just releasing one side at a time.I would be careful if you are doing it on a jack and not a ramp as it can be quite difficult at the best of times.
The joints are now available seperately from the wishbones,which makes the job a million times easier.
Just undo the pinch bolt in the bottom of the hub,knock the wishbone down and out of it's mounting hole and drill the old rivets out that hold the joint into the wishbone.You might get lucky and find that they have been changed before meaning you have to just undo the bolts holding the joint in as someone else has removed the rivets.
All you need to is remove the pinch bolt and knock the wishbone out of the hub..Just be a bit carefull that you don't pull the driveshaft out of the gearbox,and that you don't hit the ABS sensor etc.Just unbolt the old joint and bolt the new one in(using new bolts if supplied).