Half shaft(s) are only held by C-clips, very prone to pulling out in 2004 and 2005, redesigned in 2006 to strengthen case and resist half shaft pull out. Changing the side seals involves supporting front diff on jack, unbolting CV flanges, drive shaft (mark so as to be able to re-bolt in same orientation), mounting point bolts, lowering front diff. Removing half shaft with slide hammer puller or by hitting flange with rubber mallet. Then pulling seal with seal puller or by drilling a small hole in seal and pulling seal by engagement of the screw end of a small dent puller type slide hammer.
If the half shaft is pulled out, some people have been able to just push it back to reengage the C-clip in the internal groove in the side gear, although the splines on the inner end of the shaft can get messed up when it pulls out.