How to Edit a Dynamic Link Library

1. Use Spices.Decompiler (see Resources). Spices.Decompiler allows you to take any DLL on your computer and decompile it, or take it apart. You can then make edits to the contents of the DLL (if its an icon library) or make changes to the way the DLL operates (if it contains instructions). Spices.Decompiler is free to use for an unlimited period of time.
2. Use PE Explorer (see Resources). PE Explorer allows you to see exactly what is contained in a DLL without taking it apart first. If you determine that edits need to be made to its contents, you can then do so all from the PE Explorer program window. After editing, you must remember to recompile the DLL file. PE Explorer, like Spices.Decompiler, is free to use.
3. Use Resource Hacker (see Resources). Resource Hacker is a program that can edit the contents of DLLs as well as a wide variety of other Windows-based files. Resource Hacker is only equipped to deal with DLL files designed for the 32-bit version of the Windows operating system. As of January 2011, no version of Resource Hacker exists that lets you edit 64-bit DLLs.