cutter compensation or wear compensation for dummies?

Wanting to use compensation to make small corrections to adjust for cutter diameter to get more accurate feature sizes.  Is this something that can be entered using Axis UI or does this require gcode editing?  Having a hard time finding simple examples.  For example, if I mill a 1/2" hole with a 1/4" end mill and the hole ends up being 0.4990" I want to enter offset adjustment of 0.005 (radius error) without rerunning post in CAM package (Fusion 360). 

From memory, you have 2 methods from F360
1. adjust the tool diameter in the F360 tool library
2. Subject to a setting change in F360, the diameter in the linuxcnc tool library can be used to set the tool wear offset.

Please read the F360 docs as it is described

I said for dummies but I figured that much out. I am hoping for more than RTFM...

Unless G41 / G42 is used in Gcode, you can modify parts by cutter compensation. Normally from CAM, toolpath is created with toolcenterpoint with offset from selected tool. You will be bound to another pp run for changes, as you don't like. For this purpose, i create a few similar jobs, each increasing measure compensation by a small value, eg. 0.02mm. When the expected result achieved, abort. Without G41G42 active, modification from cam is the only way.

JimS wrote:

I said for dummies but I figured that much out. I am hoping for more than RTFM...

I'm sorry but I gave you the info I have. I am not going to RTFM so I can answer a question I would have to research.
Instead of being arrogant and impatient, be patient and somebody might add more detail on the question.

To be perfectly honest assuming the cutter is not of the correct diameter may not be the issue, other factors that can play part (they can accumulate), overall machine accuracy, rigidness of machine, squareness of machine, tool deflection, any backlash, speeds & feeds, cooling & chip evacuation. Messing up decimal points wont help either.

This was an interesting article & video on various methods of "making holes".
tarkka.co/2021/02/07/holier-than-thou/