Can't be answered correctly without knowing who made it.
go to: forum.m1911.org and ask your question
Follow instructions in the owners manual. Find a gun smith if you don't have one and ask for help.
go to: http://stevespages.com/page7b.htm
Which one?
take apart the whole gun
Ask a gunsmith for help
Ask a gunsmith for help or ask the maker for a manual
Best left to a gunsmith
Take it to a gunsmith and ask for help
there is no 45 pistol, however there is a 44 pistol. the 44 pistol can be found as random loot or off the corpse of someone with a 44 pistol.
.45 ACP means Automatic Colt Pistol. It IS .45 Auto.
You can get a manual at S&W's website for free.