wildish

New to the Board and need some advise. One of the kids has a 90 legacy with 140K miles and the mechanic says #3 injector went out. I had the #1 Injector replaced about two months ago which solved the problem at that time. The thing is he wants an arm and a leg for the injector. I am mechanically inclined. So how hard is it to change out the injectors? Can someone with a normal layout of tools complete it. Is there any online directions? thanks