First, you should measure the diameter of the current handlebar using calipers. Or it can be stamped on the handlebar.
Your bicycle is from 1989, so the diameter should be standard - 25.4mm or 26mm. It's more likely to be 25.4mm.

The process is pretty simple.
1) Push on the brake levers and unscrew the bolts inside of them and take them out.
2) Use a metric allen wrench to unscrew the bolt at the bottom of the stem. Take out the handlebar.
3) Carefully insert a new handlebar trying not to scratch it and screw in the stem bolt.
4) Screw in the brake levers.
5) You may have to replace the brake cables and housing to match the new lengths.

Get a swept-back handlebar called Nitto North Road, it's more comfortable.
https://www.google.com/shopping/prod...HWyWBigQ2SsIGA

There are other similar handlebars.
Category: - Ironweed Bicycle Products