NEW YORK (AP) _ Customs agents arrested four men trying to pry more than 100 pounds of cocaine from a 20-foot cargo container, but the agents did not need to ask where the drugs were hidden: they already had the fax.

Drug smugglers in Cali, Colombia, faxed four pages of detailed instructions to the suspects, including a diagram of the container's frame outlining which six ribs of the steel container contained the cache of cocaine, agents said.

The faxed guide was found taped to a wall inside the container where the men were arrested Sunday, agents said.

The instructions, written in Spanish, ''even gets down to how many laborers would be needed to take the container apart,'' said Customs Area Director Kathleen M. Haage, who directed the investigation.

The plastic-wrapped bricks of cocaine were discovered concealed inside the hollow sections of the cargo container's doors and inside the container's support beams.

Officials estimated the more than 100 pounds of cocaine would be worth $7.5 million on the city's streets.

''I was amazed,'' said Customs Special Agent Tracy Connell. ''It's the first case I've seen with any sort of diagram.''

Usually, Colombian drug smugglers will send someone who has watched a shipment being packed to direct workers on the best way to extract the illegal drugs, Connell said.

A container leasing company in Houston tipped the customs agents that the person who leased the container was acting suspiciously. Customs agents examined the container at a New Jersey storage area and found the cocaine.

Investigators followed the cargo container as it was transported to Queens, where the three-week investigation ended with the raid and arrests.

The four men arrested were Edwin Chaves Cortes, 29, of North Bergen, N.J., owner of Lockport Trucking Co.; Hector Restrepo, 33, of Queens; Elvert Jaramillo of Queens; and Carlos Aguirre, 56, of Brooklyn.

The four men were arraigned on charges of conspiracy and possession to distribute narcotics, said Robert Van Etten, a Customs special agent-in- charge.