Front strut bearing replacement

[Torq]

Hi Guys,
the strut bearing is rusty and worn on the passenger side of my 318i. Can I replace just the bearing or do I need to replace part no 1, which holds the bearing, in the diagram below.
Regards and thanks.
Torq.

P.S. If I can change just the bearing, does anyone know the size so I can order it in advance.

[magpie]

part 1 is the strut top mount,£11 ish from euro car parts,not sure on bmw price.
does it make a knocking noise when pushing down on the wing.

[swinster]

Hi,
I replaced the whole part 1, got it from GSF think was about £14. Be careful when changing, search front shock and heed the warnings.