Its really no big deal at all. Make sure you measure the distance between the bolts on your existing idler arm because there are two different idler arms for these trucks with different bolt hole distances. Just telling the parts guy the year of your truck may not suffice. As for removing the idler arm from the Center Link(big bar connecting the tie rods to the steering box and idler arm), you can use a big hammer or a tie rod puller. You can get the puller at the parts store usually with a deposit that you get back when you return it. With a hammer or puller, it should not take more than 45 minutes MAX! I say no need to get an alignment but others say to. No need to jack up the truck for any other purpose than to get yourself under there.
Remove the two bolts, loosed castle nut, wack the crap out of it or use the puller, remove castle nut, install new idler arm with orginal 2 bolts and new supplied castle nut, and torque all bolts to specifications. You might need a new cotter pin for the castle nut. Heres an install on a chevy blazer or s10 for an idea
http://www.s10forum.com/forum/f178/h...er-arm-247917/. Basically the same, you just dont have to worry about the two bolts holding the idler arm to the frame from spinning because those bolts at solid in the frame as I recalll.
The tool looks like:
