This process has gotten simpler with 10X Genomics Loupe Browser 5.0.0+. I try to keep a cache of all 10X downloads internal to JAX here (must be on the VPN):
http://singlecell-software.s3-far.jax.org/list.html
where you can download the latest version of Loupe Browser for your OS. Otherwise, head over to the 10X site:
https://support.10xgenomics.com/single-cell-gene-expression/software/downloads/latest#loupe