steering problem

Hi all

My steering starts to shake when doing about 55mph on my 1993 disco TDI. I have been told my tracking is fine and that my steering bushes? are worn (pointed to a part near front axle). does this sound right and if so how much can i expect to pay for parts and is this a job a novice can do

thanks

bushes are the rubber or poly bits between moving parts. Its up to you if you think you can do it but it aint a small job, with some big tools like presses depanding on what bushes need replacing