The city has retreated from part of its turnaround plan for 24 low-performing schools, telling principals the schools will keep their original names.

An Education Department letter to principals outlined the name change, and offered guidance on how to get the schools in shape before September.

The schools affected include John Dewey High School in Brooklyn and Newtown High School in Queens, among others.

The letter to principals says that now that it’s August, the city’s attention is focused on “a smooth school opening.”

Earlier this month, a state judge blocked the city from replacing many of the teachers and some principals at the schools. The city has vowed to appeal, but it’s running out of time before the start of the school year.

The president of the United Federation of Teachers, Michael Mulgrew, supported the Education Department’s decision.

“As an arbitrator found and the courts have upheld, these schools were never going to be really ‘new’ under the mayor’s plan,” Mr. Mulgrew said. “So it’s appropriate that they retain the historic names that mean so much to their communities and their staff.”

It’s not clear whether the city will pursue other changes it planned for the 24 schools, because it was counting on federal grants that were tied to the staffing changes blocked in court.

The letter to principals also provided information about how to staff their schools in the next five weeks and told them the department would help get accurate information to eighth graders who will be selecting high schools this fall.