Overhauling Hi-E hubs and changing axle length is covered in the archives. To replace the bearings you need to unlace the wheel and pull the flanges off the central barrel. See below sig for a sample from the archives:
Mark Bulgier Seattle WA USA
Archive-URL: http://search.bikelist.org/getmsg.asp?Filename=classicrendezvous.10507. 0 590.eml From: Eugene Powell <radfin@SpiritOne.com> Subject: Re: [CR]Re:Hi-E re-spacing questions Date: Wed, 13 Jul 2005 08:58:42 -0700
Harlan sent me a pile o' spacers (I have both the steel and alloy ones)
and a few axles years ago, I've got the ones you need. Or, as you've got the shop to do it, I could take some pics and measure them. They look pretty straight forward, duplicates should be no problem.
To get it apart,
Use an old QR skewer to gently tap off the end cap by inserting from the opposite side and allowing in to rest off center and tapping gently. Mine came off very easily. If yours are more stubborn you might
have to rotate and repeat several times. I know of no bonding agents or
other adhesives used on the axles, nor are there any threads. All slips
together, and often slides apart if you don't keep a QR in place.