Yes the plastic inner section fits from inside the car.
They can be a real pain to get in ..... As for replacing one on a Sierra, don't even want to go there
It may help if you lubricate the rubber with a little soap, it'll help to prevent the plastic draging on the rubber
If re-using the original, make sure it is in tip top condition !! .... A fraction of play between the two plastic parts, will seem like a mile at the wheel .... A very frequent MOT failure on the Sierra.
New bush kits are to be had on Ebay, for not a lot
