my approach
I have an (American built) Hunter 35 with a plastic packing gland fitting. I just repacked it whilst the boat was on the hard. To do so I loosened all hose clamps around the rubber "hose" then eased the plastic gland towards the engine along the shaft, completely out of the hose. Next I used a fine, thin, stiff rod. Inserting this from the aft end of the gland, I pushed the old packing out. There were three rings in there in addition to three "hard" rings, one metal and two plastic. By the way, some shops sell a tool that will act as a pick for flax removal. These have some sort of hook or fine-threaded screw on their tips.Following removal of the old wax rings, it is laborious to get new rings in. I first reinserted the gland in the hose and tightened the clamps. The new rings first need to be cut properly, then individually fit in. I found it was easiest to insert and pack each ring separately. The hard rings which remained on the shaft were kept at the forward end of the gland and a new ring inserted aft of the hard rings. Then tighten the packing nut into the fitting, compressing the wax ring. If these instructions are not understandable, you can contact me via email via this web site's mechanism under a boat owner's link.