With Sears and the like, I think it’s best to go to a smith. But, If you wanna diy it, there’s a kuhnhausen shop manual for 1911s on my google drive. It’s misplaced in the books/pamphlets section rather than the gunsmithing and armorers manuals.
https://drive.google.com/drive/folders/1JSplqF9XaDDQTz1a7myKucHnFSQx2oBA?usp=sharing
https://drive.google.com/drive/folders/1JSplqF9XaDDQTz1a7myKucHnFSQx2oBA?usp=sharing