rack and pinion

[S13CoupeLover]

My dad mechanic told us that my rack and pinion on my 240 was leaking. Once i get the car back from my other mechanic i'm going to look under the car and check everything out. but if it does come down to me replacing the rack and pinion, how hard is it to replace it?? or should i buy the part (so i don't really get screwed for the mark up price they'll give me) and have my alignment shop put it in and only pay for labor?

also if i need the R&P replaced is therackdoctor on ebay a good seller?and is there any good write ups on how to remove/install the R&P??