is it better to let a professinal install them cus thats what the haynes book says. Other then getting the bearing pressed in what else is so hard? cant i just take it off and have a mechanic press them in?

yes, you can get everything done yourself until its time for the press, then goto a shop with a press and pay a tech $20 to press them for you real fast, then go home and finish the install.

opps just been told this should be in the suspension section think a mod can move it?

I always buy the bearings and seals from Toyota and have a local shop install them. I have access to a press at work, but since its best to get an alignment afterwards (a bad bearing can throw off the alignment) it just doesn't seem worth the time to do it myself.