Where did you get 'Axes Manager' from ?
Do you mean something else ?
There is a 'UCS Manager' RBZ [DBUR_UcsManager.rbz] available from the SketchUcation Pluginstore
http://sketchucation.com/pluginstore?pln=DBUR_UcsManager_v1_0_0
When properly install it has a subfolder named 'DBUR_UcsManager' in which is a Resources subfolder, which contains the PDF [UCS Manager.pdf].
The EWH includes a newer one by Didier named 'Axes Manager' ?
With similar files/subfolders 'DBUR_AxesManager.rbz' etc.
There is a Resources subfolder containing 'Axes Manager 2016.pdf' ?
So How did you install it ?
Using Windows > Preferences > Extensions > Install Extension... button ?
I have just installed both from their RBZ and they both include the PDF in the ../Plugins/DBUR_XxxxManager/Resources subfolder...