Remove the plastic cover at the base of the wiper arm, it just snaps off. With the cover removed you will see a 13mm nut, remove the nut and wiggle the arm off.
Need to know what year you have.
If only one wiper is working then you have a linkage problem. There is an arm that runs from one side to the other. It has bushings that wear out. You can also have a stripped spline where the wiper arm hooks up.
Need to know what year.
Very Carefully
Pop up the plastic cover over the pivot point, remove the metric nut and wiggle the arm off. Make note of the position of the old one when installing the new one.
How much torque do I use to tighten the idler arm
Yes you can.
The 1998 Chevrolet S-10 wiper blade sizes are 20" wiper blades on both sides front. Do not buy by length-only however. See Sources and Related Links below for more information. Since there are over 22 different wiper arm attachments - be sure to lookup exact wiper blade part numbers by vehicle make, model and year for the brand wiper you decide to purchase. This ensures correct length AND correct attachment.
Lift wiper arm up off windshield it will only go a few inches then stick small screwdriver thru small holes at base of wiper arm to keep tension off and the arm should pull right off worked really easy.
Need to know what engine it has.
Lift wiper arm so that it is at about a 90 degree to the windshield. It should stay there. Now look near the base. There should be a little lever. You should be able to fit a screwdriver between it and the wiper arm. Pry the lever sideways and once it opens up a little you should be able to lift the wiper arm right off.
Assuming that you mean "wiper blade" (blade and frame) which are replaced often rather than "wiper arm" (piece from the spindle at the hood to the wiper blade) which are rarely ever replaced, the 1988 Chevrolet S10 Pickup takes 16" wiper blades on both sides front. See sources and related links below for more information. Since there are over 22 different wiper arm attachments, do not buy wipers just by length only - be sure to lookup exact wiper blade part numbers by vehicle make, model and year for the brand wiper you decide to purchase. This ensures correct length AND correct attachment.