1. erbil -> erwil
b < -> to w, or m < -> to w
is in Kurdish a very normal process.
Example:
wîn ("See" Presense Root in Kelhuri) -> bîn (Kurmanci, Sorani: dibînim, ebînem)
nam -> nav (English: Name)
2. erwil -> ewlir
Here we can see real loud adjustment / shifting, not loud transformation by normal "loud shiftings".
This is in Kurdish also very normal. We see this also in:
befr (Sorani) -> berf (Kurmanci)
Of avesta: vafra (befr in sorani is here nearer to the Avesta-form, note: in zazaki it is: vewre

In English: Snow
3. And then came an
i -> e loud-shift.
ewlir - ewler
This in kurdish also a normal procedur. Example:
ters (sorani) -> tirs (kurmanci)
In English: fear
Or: be (sorani) -> bi (kurmanci)
In English: with
And at the end came the "h":
4. ewler -> hewler
This is in Kurdish also very normal, example:
esp (sorani) <-> hesp (kurmanci)
in english: horse
Other examples:
asan -> hêsan, erzan -> herzan, ewr -> hewr
This thesis supports also a student of indo-european languages of a university. If its possible, that "istanbul" comes of "konstantinopel" (this is a linguistic fact), than my thesis also can be possible.