Ken, you should be able to copy a picture then just paste it in.
Sometimes new centreboards will have an oversized epoxy plug to drill the bolt hole through, otherwise if the bolt goes through timber it will quickly wear any varnish away. Use the old board as a template for the hole position, check the existing board to see if the hole is perpendicular and be careful to match it to avoid any alignment issues with the centreboard case.
It is best to fit the centreboard on dry land – either careen the boat onto its side and secure it with the jib halyard (not the main), or if the boat is shuffled back a bit on the trolley there should be enough wiggle room to remove it from inside the boat.
bob