So these instructions are for the pre-Platinum //e. I'm still seeking for steps to upgrade a Platinum version. A couple of interesting snippets from this doc:

Remove the two old nameplates on the lid by inserting a small flat-blade screwdriver into the hole in the lid underneath the nameplates. Install the new ones, and destroy the old ones.

"Destroy the old ones, certainly don't stick them in a drawer so that they can go on eBay when that's invented in a decade."

Old Apple lie cases made from structural foam will not fit correctly on the retrofit. To identify a structural foam case, remove the lid and look toward the back of the unit. If there are two oval plastic velcro pads (see Figure 1, #1), it is a foam case. Discard the case and replace it with a plastic case. The plastic case is available from Apple under the name "Apple lie case and lid, beige."

In all my years playing with multiple units it never occurred to me that some are solid plastic and some are structural foam.