To recall their electors. At least, the state Senate cannot. Maybe someone else (governor?) can?
https://www.washingtonexaminer.com/news/arizona-senate-powerless-recall-electors-president
The Arizona Senate lacks the authority to recall electors, the legislative body’s Republican president said on Friday.
That statement by Karen Fann came in response to fellow state Sen. Wendy Rogers, who called for a new election after the Arizona Senate held a briefing in which contractors hired for its 2020 election audit in Maricopa County said they don’t have enough information to complete a report.
Fann told One America News Network, a cable news channel with a reporter who is controversially helping to fund the audit while covering it, that the Arizona Senate has the power to help the auditors get the materials and information they say they need (likely through more subpoenas, along with a door-to-door canvass), but the question of decertifying the election will be left up to others.
She is correct that the State Senate alone can’t recall electors. The entire State Legislature, both houses, would have to do it.