To install the addin, first go to menu -> Add-Ins
If you are trying to install an add-in in another location, you can click on the browse button in the add-in dialog box to find the add-in.
Locate the folder that stores your add-in, select the add-in and click OK with the left mouse button.
Once the add-in is listed in the list of Add-ins dialog box, place a check on the add-in and click ok.
The macros and custom functions in the add-ins will be available for use in your computer.