One cool mod for the CR-10 is to replace the hot end, and here's the CNC Kitchen video showing how to install the Titan Aero with an E3D Volcano nozzle.
Once its installed, the best place to feed filament into it is directly above, so you'll need to drill a hole in your enclosure. Check out these pictures showing the ideal location of the spool holder and hole. When drilling new holes into acrylic, be sure to use masking tape on both sides, and only press the drill slowly and gently. Once you're finished, though, this is the ideal location for filament into the Titan. Note that the spool holder should be placed close to an edge of the enclosure when using a big 2.5Kg reel like shown in the pictures.