Right-click llP1LC.7z.001 , hover over 7-Zip , and select "Extract Here" or "Extract to..." .
If you don't have an extraction tool, the official 7-Zip website is the standard, though others like WinZip or Unzip One also work.
If extraction fails midway, one of the volumes might be incomplete. Check the file sizes; split volumes (except for the very last one) are usually the exact same size (e.g., all 100MB).
This usually happens if you try to open the .002 file directly instead of the .001 file.
You should only ever attempt to open or extract the (the one ending in .001 ).