Show that $f$ is still integrable after altering it at one point

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Let $f$ be an integrable function on $[a, b]$.

Show that $f$ remains integrable on $[a,b]$ if we alter it at one single point and that this alteration does not change the value of the integral $\int^b_a f(x) dx$.

In lecture we have proven this statement by splitting up the altered $f^*$ into the old $f$ function and an indicator function. This approach seems perfectly reasonable for me.

However, I am curious about whether it is possible to show the statement without an indicator function.

Any comments or thoughts on this are welcome.