Answer
It is permissible to use a tweezer to remove facial hair. All the hair within the nostril should not be removed as it is there for our protection, yet if hair in the nostril is coming out of the nose can be removed.
The hair on the penis does not have to be removed. Only the pubic hair which is just above the private parts below the navel has to be removed.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai