You say your bushing is installed from the bottom and you can't reach it with a tap?  Use a 1/4" Drive socket extension to extend it out far enough to reach.

Bushing removed.  If it is not too worn and you did not run the tap in too far, you might be able to re-use it.  But you really ought to install a new one.  You decide.

Screw a bolt into tapped hole.  This is what you will be driving against to knock the bushing out, nest step

The bushing may be installed from the top or bottom, depending on model.  If installed from the top as shown here, you would drive it out from the bottom

So....Since I take pride and satisfaction in making high quality tools at a reasonable price, if I cannot make a tool that is going to work well every time under all conditions, I prefer not to make it at all.  There are other ways to get the bushing out, one of which I'll try to describe here

I've made and sold lots of these tools with no complaints.  However, there have been a few cases where it doesn't work.  Those usually are where the bushing is worn and the shoulder on the tool goes down through the hole in the bushing.  The same thing may happen if the bushing is extra tight in the hole due to corrosion, especially in salt water.  I cannot make the shoulder or "step" that contacts the bushing wider, because OMC made gearcases with a wide variety of hole sizes that the tool must pass through.  Therefor, the tool must be thin enough to pass through the smallest drillings through the gearcase, which makes it unreliable for the intended use.  The OMC factory Special Tools Offering suffers the same problem.

SHIFT ROD BUSHING REMOVER.

Insert a 1/4" or smaller rod into other end of bushing, against the bolt you just screwed in.  Use a hammer to tap the bolt and bushing out.

Use a 5/16"-18 thread tap, tap threads in the bushing.  If you intend to try to reuse the bushing, turn the tap in only 2-3 turns.  A "plug" tap would be preferred over a "taper" tap.

DISCONTINUED---HERE'S WHY