How to Rewrite a Chorus That Isn't Working
A chorus that isn't working almost never needs a full rewrite. It usually has one specific failure. Find it, fix only that, move on.
Problem 1: the title isn't in it
Most modern choruses state the title in the first or last line. If yours doesn't, check whether the title is strong enough to carry a chorus — and if it is, put it there. Most chorus-is-flat complaints dissolve once the title does structural work.
Problem 2: it says too much
A chorus with three ideas has no ideas. Count the distinct thoughts in your chorus. If the number is greater than one, you have verse material pretending to be a chorus. Strip until one idea remains, then repeat the repetition.
Problem 3: the melodic peak is in the wrong place
Sing the chorus and notice which syllable lands on the highest or most emphasized note. Is that the emotional core word? If the peak lands on a throwaway word, rearrange the line so the peak lands on the word that carries the weight.
Problem 4: it repeats the verse's rhythm
Choruses need to feel rhythmically different from the verse around them. If your chorus scans like the verse — same meter, same cadence — the listener experiences it as more verse. Break the rhythm. Shorter lines, longer lines, a hold, a leap.
Problem 5: it's too specific
Verses can be specific; choruses usually shouldn't be. A chorus too tied to a particular detail loses the universality that lets strangers sing along. Pull your chorus up one level of abstraction and see if it opens up.
Rewrite only the problem you named
Don't rewrite the whole chorus. Fix the single thing you diagnosed, sing it back, and judge. Iterative edits compound; full rewrites usually trade one problem for a different one.