Imaam Ibn Baaz (rahimahullaah) said:

That which is obligatory upon the society is to give the Scholars their due standing, and that a person works in order to direct them and advise them, and that he is eager to defend them and not to backbite them and to keep their honours safe. For there is not one of them who is infallible and errors and slips can arise. So when the error and slip occurs, it is obligatory upon the Scholars to inform each other (of such slips) with a good manner, and with good expression until the error ceases (to be) and the truth becomes apparent.

In the lecture Sharaf al-Ilm wa Aadaab Ahlihi as occurs on page 7 of the book, "They Turned Dammaaj Into a Torch of Fire After It Was a Torch of Light" (read here).

You can learn excellent manners through the example of Yahya al-Hajuri. Study his speech and behaviour and do the exact opposite: Look at his use of the most vile and foul of language against the scholars such as Shaykh Rabee (see this article for evidence), words such as "affaak (fabricator)", "kadhdhaab (liar)", "speaks out of following desires and shaytaan", "strives to set up a hizbee centre in Fayoosh", "person of destructive calamities", "calumniator", "the desires fester and flow in him", "may Allaah cut your tongue", "may Allaah fight you", "put my efforts and your efforts on the scale and we will see whose is more..." And that's just for Shaykh Rabee! What do you imagine for others? And then his vile language, "Piss on it", "Piss on it", "Piss on it" (repeated, because he frequently uses this dismissive phrase), even Imaam al-Shaafi'ee and his fiqh was not spared in this regard. Al-Hajuri says "an old woman's fart" about one of the Shaykhs of Madinah, and "may you perish, just as the two hands of Abu Lahab perished and perish he!" to another of those Shaykhs. And that is just the tip of the iceberg...

Also put the advice of Imaam Ibn Baz alongside the observation of Shaykh Muhammad bin Abdul-Wahhab al-Wasaabee (see here), who is the senior-most of the students of Shaykh Muqbil:

The maraakiz are many and the duroos are many, so there is abundance so fear Allaah and keep away from qeel and qaal (i.e. speaking about other maraakiz and students and scholars), speaking about the Shaykh of markaz and speaking about this and that. This is what destroyed Dammaaj. "Allaah does not change the condition of a people until they change what is with themselves" (13:11). The verse contains the precursor (muqaddimah) and the end-result (khaatimah). When they change what is with themselves, the situation will be made to change over them. When they change then the end-result will come to them. There is no doubt that Dammaaj has been changed, but this did not happen until they changed, this would not have happened. If they remained upright, upon respect of others, not having mockery, belittlement, abuse of others, the situation would not have changed upon them, but they changed. When you correct or refute a Sunni, do so with utmost adab, within the limits of the legislation. If they remained like this, the situation would not have changed upon them. But when they changed, the situation was made to change upon them. Do you want to experience the same thing as them? Preserve your time, wherever you may be in any markaz or any centre from the centres of the Sunnah. Show respect and manners.