To replace a Bulova watch band, remove the old band with a spring bar tool, clean inside of the lugs, place one side of the spring bar into the lug and use the spring bar tool to slip the other side in. Do the same on the other end of the watch.
Before beginning, cover the areas around the band with painter's tape, as it helps to prevent scratching the watch. Use a spring bar tool to remove the old band by slipping the flat end of the spring bar between the lug and the band. Most spring bars have a lip at the end that can catch the pin to pull or push it away from the lug. When doing this carefully, the band should come out.
With the old band out, slip the spring bar into the hole at the band's end, and then push the band between the lugs. Compress the spring bar on the other end to put the other side of the band into its lug. Use caution, as the spring bar can easily fly away. Repeat this action on the other side of the watch to ensure both bands are secure. When the bands are in place, remove the tape and wipe the watch with a soft cloth to remove fingerprints.