Apex107-005-2The following are the installation instructions for installing the Apex Plus 3 Base Pad on standard capacity magazines for the Smith & Wesson SD model pistols.   Warning! Wear Safety Glasses While Handling Magazine Springs; Springs May Be Under Extreme Compression. 1) With the magazine unloaded, remove the factory magazine base pad and base retainer. Refer to your pistol owner’s manual for instructions to do so. 2) Set aside the factory magazine base pad and retainer; you will not need them for the remainder of this installation. 3) Compress the magazine spring into the magazine body until it sits entirely within the magazine. 4) With the spring compressed, slide the magazine extension on from the front to the back. The magazine spring will expand and sit inside the magazine extension. 5) Ensure that the magazine extension is fully seated on the magazine and then use an allen key to tighten the retaining screw. 6) Test the magazine in order to ensure proper function by loading it to capacity and watching for any issues during a manual unloading of the first five (5) rounds. The cartridges should be consistently pushed against the feed lips. To remove the the base pad simply reverse the process, keeping in mind that wearing safety glasses is always recommended as the magazine spring may be under extreme compression. 1) Unload the magazine and then use an allen key to loosen the retaining screw. Once the screw is loose, slide the magazine extension off from rear to front.