2000 Ford Ranger XL 4WD 3.0L V-6 170,000 mi.

I have a lot of sqeaking and screaching noise in my suspension when going over bumps or turning. I was told by the Ford dealership service advisor that I could grease my upper control arm bushings, lower control arm bushings and tie-rod end ball joints. He said to look for the grease nipples. I put my truck up on a rack and removed both front wheels. It appears there are not any grease nipples in the locations specified by the service advisor. On top of the upper control arm there appears to be a metal cap. Is the grease nipple below this cap? Can this cap be removed and can I apply grease in the locations specified or am I going to have to take the upper and lower control arms apart to replace the grease in what appears to be a grease boot just under the upper contral arm where it attaches. Can this "joe homeowner" put grease in the locations needed or am I gonna have to pay a mechanic to take the thng apart just to get some grease in these joints? I spoke to another "shadetree mechanic" and he said it appears all the grease wells are sealed at the factory. Is this true? Is it not possible for me to grease the joints on this truck with a grease gun?