The phrase "necessary alterations" is correct and commonly used in written English.
It refers to changes or modifications that are required or essential. Example: The contractor completed the renovation of the old building, but there were still some necessary alterations that needed to be made before it could be occupied.
"You son of a bitch!" I sat down at my desk, and while he glared at me, I began to make the necessary alterations in the duty roster.
On the topic of revising, Munro said that though she often could tell what a story was missing, she had to spend time figuring out the right way to make the necessary alterations.
In many buildings, the board's consent to the amendment is also necessary, and in all cases the board must approve the necessary alterations.
One could tell the story of the new media law as the old story of bureaucratic obstacles hindering governments from making necessary alterations – even more so if we keep in mind that the old law was passed in 1996 and was thus primarily a "post-communist" law.
Any necessary alterations would add additional weeks to production.
You're referred to a local tailor to get all your measurements, and they can also do any necessary alterations just before the wedding.
Paragraph 2 describes the testing and, if necessary, alteration of these methods.
In order to create a H. jecorina strain which expresses a constitutively activated version of GNA1, a construct comprising the entire gna1 gene, but with the necessary alteration in the open reading frame was prepared.
The Secretary, in consultation with the Bureau of Indian Affairs, shall initiate a program to conduct necessary renovations, alterations, repairs, and reconstruction identified pursuant to subsection (a) of this section.
The first tumor probably developed from one of the more dominant clones scattered on the right lung after acquiring the necessary mtDNA/nDNA alterations sufficient to promote tumorigenesis.
Compliance with administration of the treatment was confirmed and, if necessary, dosage alterations were made and additional therapy was added.
