There will be extraneous string length while replacing the 5th and 6th (furthest to the right) strings. Using a wire cutter, you may opt to trim the length of these strings.

Stretch out the replacement string and cut it about 3-4 peg lengths away from the peg of the string you're replacing. In this case, you are replacing the 5th string and will cut the string near the 2nd string peg.