no need to remove, lift or do anything with the transaxle when replaceing the left hand lower arm,cut the top off the bolt with a small hacksaw and pull the bolt out from the bottom,when the new arm is fitted replace the bolt with a new one putting it in from the bottom with the nut under the transaxle.
drill a hole through the nut and bolt and insert a split pin through to avid unscrew, woks a treat.
as for the rivited ball joints a bolt on replacement from ford or motor factors is available in u.k,just grind off old rivets remove joint and replace with bolt on version.
cheep lower arms sold by motor factors in the u.k are a third the cost (£30) of fords own, the only problem is the rubber bushings will not last,i fitted my last arms 12 months ago 10,000 miles on and they have failed the mot test, the rubber bush on the drivers side had dropped out and one had actualy split on the passenger side.i have been told from various sources that ford arms will outlast factor arms by up to six times ?