Carefully evaluate all risks and make the appropriate decision.
If decision is "go" take an experienced guide. (go to 4)
If no guide available study field guide and check map reference. There are so many adits and levels in the Copper Mines valley that it's possible to enter the wrong one. See health warning in previous post.
Wear appropriate clothing. It's cold in them there mines.
Protect your head. (Copper miners were either dwarves or permanently bent double.) Wear a helmet. A miner's helmet is ideal, but at the very least you want one of those builder's helmets that are available in builder's stores.
If using builder's helmet, get one of those halogen lamp headsets that are worn by walkers, attach to helmet and secure using strong electrical insulation tape. Mines are slippery and it's much easier (and safer) to progress if both hands are free.
Post someone outside. If no one available, tell responsible person: contact details of mine rescue service; when and where you are going (with precise map coordinates) and what time you will report back.
Explore mine.
Take only photographs, leave only footprints.
Report back to the responsible person as soon as possible after the mine exploration is complete.