Air Conditioning - decommissioning split system

As part of a remodel, I need to move the ground mounted 3 1/2T condenser/compressor and replace the air handler. Also, will replace the 3/4" line with 7/8" line. The air handler will upgrade to a multispeed trane.
I need to basically remove the freon lines, install/move the big pieces, then call the a/c guy for charging and hookup. Is there a trick to removing the freon line? One person told me to run the a/c, then turn off the valve on one of the freon lines, wait 30 seconds, then shut off the system. Do I then crimp both lines before disconnection? Do I need to monitor the compressor current or pressure during this 30 seconds?

thanks in advance.

You are best to call in the pro and have them remove the charge on the system.. And let them do the job.. If there something goes wrong, it's thier repair.. Not your's.

This job requires a refrigerant recovery license. Gauges and a recovery unit are required to pump the condensing unit down and recover the refrigerate left in the lines down to 10 inches. Its not a do it yourslef job.