Sight tools are great if you want to pay a lot for a good tool. What I've always done is use a brass punch and a hammer. The rear sight is fits tightly in the dovetail but it can be moved with with a hammer and punch. If you take your time you can adjust the sight without marking or damaging the sight.
USAF Retired, CATM, SC CWP, NH NR CWP, NRA Life/Endowment/Patron
To preserve liberty, it is essential that the whole body of people always possess arms, and be taught alike, especially when young, how to use them... -- Richard Henry Lee, 1787