How to randomly change a digit in a string

I have a string = 00101 How i can randomly change one digits of that string? Ex: 00101=>00100

Answer 1

[Joseph Wilson]

string1 = '00101';

digit_change = randi(length(string1));

digit_val = str2num(string1(digit_change));

digit_new = num2str(~digit_val);

string1(digit_change)=digit_new;