Followed all the steps to a t(tee?). Got this error both times I tried, which is why superuser.apk was already pushed.
[*] Pushing root tools...
2961 KB/s (366952 bytes in 0.121s)
4154 KB/s (1867568 bytes in 0.439s)
4246 KB/s (1578585 bytes in 0.363s)
pkg: /data/local/tmp/Superuser.apk
Failure [INSTALL_FAILED_ALREADY_EXISTS]
[*] Rooting phone...
error: only position independent executables (PIE) are supported.
[*] Cleaning up...
[*] Exploit complete. Press enter to reboot and exit.