In order to install GTA San Andreas Powerful Mode Mod, you will need to download it first using the first link from Google search engine. Once you download it, extract the installation package using WinRAR or WinZip and open the READTHIS.TXT file. It contains the installation instructions for this mod. Basically, you need to launch the installer and to click Next:
After that, press again Next, use the Browse option to select the folder where GTA San Andreas is installed, click once again Next and follow the on-screen instructions.
Note: You can also download the mod from the review page of the product. Just press the green Download button, save the file to your computer and follow the above instructions.