More than 1,000 troops from both countries are stationed around the temple complex.
Cambodia and Thailand agreed last month to withdraw their forces from a small patch of disputed territory near Preah Vihear.
The border dispute erupted in July, after three Thai nationalist protesters were arrested for trying to illegally cross into Cambodia to reach Preah Vihear.
They were angry that Cambodia had won world heritage status from the UN for the ruins last month, which Thailand has long claimed despite a World Court ruling giving the ruins to Cambodia.
Foreign ministers from both countries are set to meet on Monday and Tuesday for further talks on the deal.
"The redeployment of the troops that we have agreed to will finish before the ministerial meeting on August 18," Neang Phat, the Cambodian army officer, said.
He said the remaining troops would be allowed to carry only simple rifles and guns.
Their future positions would be determined after the ministerial meeting next week, he said.