I bought two 9mm Shields, one for me and my wife... The first time I took mine apart, I just pulled the trigger and did not use the sear disconnect lever.. Put it back together and the pistol would not cock the hammer. Called S&W and they said send it back.. I did and got it back about two weeks later, with a letter saying that they had replaced part of the trigger assembly and told me, in the future, use the sear disconnect lever.. I now have a Shield .45 and I use the sear disconnect lever every time I dis-assemble my Shields.. Using the "pull the trigger" method works, but you can damage your Shield. It is not if, it is just when.. S&W put that lever there for a reason....
Now let me get my flame suit on before the nasty comments start...