1)
Lift the playfield. You'll be working on the left hand side of the
machine. Underneath the playfield, loosen the three large nuts around
the lagoon plastic. No need to take them off.2) Lower the playfield onto the cabinet so that you can get at both sides of the plastic.
3) Remove the Creature hand plastic - three screws, two wood thread and one machine screw.
4)
Remove the two screws that hold in the lagoon plastic, and the screw
that holds down the ball guide. The ball guides on the left and right
should now lift enough to work the lagoon plastic out.
5)
Here's the plastic lifted out of its groove, and sliding under the ball
guide. This is not a tight fit, it should slide easily. You don't want
to scratch the surface.6) Slide the old one out and slide the new one in. Seat it in its groove.
7) Replace the three screws that you removed in step 4.
8) Replace the Creature hand plastic, reverse of step 3.
9) Raise the playfield, and tighten the three nuts that you loosened in step 1.
10) Put the playfield back down and close the machine up.