Procedure for changing plugs

What is the procedure for removing the metal surround and rubber boot to prevent damage to the plug wires?

Pull them directly in line with the plug and they should just pull off. If you pull them at an angle they are very difficult to remove.

I changed my plugs at approx 100K miles and the tips pulled out on 4 of the wire boots. You probably should just go ahead and buy new wires. I had to spend about $50 for new ones at Autozone.

What is the procedure for removing the metal surround and rubber boot to prevent damage to the plug wires?

I have used the twist left and right at plug boot....and when I can get the boot to rotate on plug I the pull straight out......If the boot is firmly bonded to plug there is a tool that will grab the butt end of the plug boot then when pulling out it causes the boot to expand easing the release from plug..... now if GM /previous owner used a silicone dielectric grease in the plug boot this is not necessary ... obviously whenever doing this the ohm meter must be used to ensure wires are ok and if installing new wires make sure the new wires are close to OEM spec's......new does not mean good!!!!