Issue with mame AbdulMunaf. Should I change it.

Recently I joined classes for learning Arabic, at
which my arabic teacher said that my name i.e.
AbdulMunaf is not a good name. As Munaf was the
name of pre-islamic idol the meaning of name is
Slave of Munaf an idol, and thus must be changed.

I searched internet to find the meaning and found:
1) Munaf/Manaf was indeed name of an Idol.
2) AbdulMunaf was name of great gradfather of our
beloved Prophet Muhammad(P.B.U.H.).
3) Meaning of Munaf is "the Exalted/ the high",
and who is more high than Allah SWT. So this may
mean Slave of Allah.

So now I am bit confused.

Now my questions are:
1) Should I change my name?
2) If I change my name, should I have to change
is officialy i.e. change it in all my degrees,
documents etc?

Allah Hafiz