Please help with plugin installation ImageJ Microtubule Tracker

I am attempting to install MicrotubuleTracker - ImageJ
However, when following the instructions they appear to be designed for Fiji users, as the Help->updates option does not appear. I have downloaded the zip folder on github, however instead of having a main .jar file which can be installed in ImageJ by Plugins->Install->Open, the file is large and I am unclear how to install. Thank you