The aluminum or steel retaining rings that hold in the wheel bearings on front or rear wheels can be removed easily without any special tool.
All you need is a firmly mounted bench vise and some drill bits. I've used this method since the '70s, and it works much better than the factory tool and procedure.
First, drill out any stake marks between the retainer and hub to prevent damaging threads on removal.
For the rear wheel, find 2 drill bits the size of the holes. If you don't have 2 the same size, get the next larger size and drill them out. If the holes are boogered up, drill them out. They don't have to be the right size or the same size, just as long as they fit snugly into the hole, and you can clamp them in the vise together.
Measure how far apart the holes are and put the drill bits that distance apart in the vise, blunt end up, sticking up about 1/4".
Put the wheel upside down onto the drill bits (or bar), and make sure you are turning the wheel clockwise as seen from the top (on left-hand threaded retainers).
For the front wheel, cut a piece of bar stock so that it fits into and across two slotted recesses, clamp it in the vice, and remove with the same procedure.
With this method, the tool is secure, and the weight of the wheel will help keep it in place, and by turning it by the rim or tire, you have tremendous leverage and control.