Steering arm

[beechymonza]

I took my car 2 be tracked and balanced up yesterday, As i have fitted new lowered suspension and new alloys and wheels, 
The bloke got it on ramps and b4 he started found some movement in my wheel, He told me my steering arm was knackered and moving slightly at the joind inside the rubber gaitor thing,
Had the car 11 years and never changed this , So what im asking is this a big job or fairly easy,

[beechymonza]

I just looked on Euro parts, And do i need 2 buy the whole lot both sides cause they coming in at about 100 quid i think, Mine is power steering 2,