In article 8f_Kf.3814$6H4.366
@fe28.usenetserver.com, ignoramus3408
@NOSPAM.3408.invalid says...
I have this Black and Decker 450 RPM drill:

When plugged into a GFCI outlet, it leaks electricity to ground and
pops the GFCI breaker.

My question is, what is the most likely culprit and how to approach
repair of it.

It trips GFCI outlets; repair it or cut the cord off
and throw it away.

If you need to ask how to repair it ... cut the cord
off and throw it away.