To change a safety or other parts of your 1911, there are youtube videos, the Kuhnhausen books, an Ed Brown CD on customizing.
Brownells has a good "how-to" in their tech notes.
Just make sure that your completed work can pass the safety tests.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)