If you’ve [made a change [that you feel [would [benefit the community
I’ve bracketed the subordinate clauses. There are four in all.
The understood subject of "made" is "you", and of "would" and "benefit" is "a change".
The first example you gave is in the correct form however for clarity the "How" should be removed in the second example. However, I am not sure what your context is and there is a third form.
Can is a modal verb they provide additional information about the function of the main verb that follows it.
Would you mind telling us how we can improve XXX? is ...