הלכה על זבחים 128:21

From the laws of the commandment is, for example, that which they, may their memory be blessed, said (Zevachim 64b), "How does the priest grab the fowl sin-offering at the time of melikah? He grabs the fowl's two legs between two of his fingers and its two wings between two of his fingers, and he stretches its neck upon the width of two of his fingers and does melikah. And this is from the hardest services in the Temple." But if he alters and grabs any place it is [still] fit. And any place on the altar is fit for melikah (Zevachim 63a). We can say that the explanation of this is also to quicken the matter of the poor person - and hence, it has no specific place. And the rest of its details are elucidated in Zevachim (see Mishneh Torah, Laws of Sacrificial Procedure 6).