Download latest glider guns from https://github.com/ceebo/glider_guns/archive/master.zip
Decompress archive to a folder, and open that folder.
Inside the newly created folder, everything will be unpacked to a folder called glider_guns-master.

Copy and paste the contents of _this_ folder (containing this readme file) --

    glider-gun-builderv2.7.py,
    'template' folder,
    'glider_guns-master' patch folder
    
-- into your newly created folder.

If you do this correctly, you will be asked if you want to overwrite 35 files inside
glider_guns-master/fixed/.  Click to approve the replacement.

In Golly, run glider-gun-builderv2.7.py
New folders 'guns' and 'LHguns' will be created in the same folder as the script.

The script works according to the current README, so it will not copy over the p1024 gun
unless the appropriate README line is updated:

1024 (3430, 'fixed')

[As of 6/7/2018 this change to the ceebo/glider_guns-master README has not yet been made on GitHub.]