Right way is an end mill in a mill, usual way is a rat tail file, fixing
lots of them is a special fixture with a drill bushing.

Fred wrote:

Drilling 1/4" holes on a 1/8" thick mild steel plate on a floor drill press
but a few of the holes were off. Try to corrected it on my drill press to
widen the holes with the same 1/4" drill bit the bid just deflected from
side pressure. I do not want to use a larger bit since it will make the
holes too large. I then try to corrected it with a Dremel with one of those
small cylindrical grinding stone attached to a 1/8" shaft to get in the 1/4"
hole but the grinding stone only lasted about 10 seconds before
disintegrated. So what is the right tool/method just to widen those holes on
one side?