Please upload the patch into your Magento root directory and run the appropriate SSH command:
For patch files with the file extension .sh:
Example: sh PATCH_SUPEE-1868_CE_126.96.36.199_v1.sh
For patch files with the file extension .patch:
patch –p0 < patch_file_name.patch
Once that is done, refresh the cache in the Admin under “System > Cache Management” so that the changes will be reflected. We highly recommend you test all patches in a test environment before taking them live.
For further instructions, see: Installing a Patch for Community Edition