I take no credit for this. Got this from Answerbag.com -- worked on my 2001 S-10.
Unscrew the bolt at the base of the steering shaft just before the steering box. Remove it completely, and set aside. Note: You may have to turn your steering wheel to display the bolt. (On the 2001, this bolt is covered by an easily-removed plastic cover that snaps together.)
Now just simply slide the shaft towards the firewall. If it doesn't come easily, I like to use a wrench and small hammer to lightly tap it off. Sometime a large flat head screw driver or pry bar will work.
Once you have the shaft off of the steering box, pull it completely out, and set it aside. This will give you plenty of space to work with. It is also surprisingly quick to do all of this also.
Now have at it with the spark plugs.
To install, just simply do the opposite of removal. Lining up the steering column shaft takes a little patience and maybe some WD-40 to get it to slip on. Use that big screwdriver or pry bar leveraged against the undercarriage to help push the parts together.