Sounds good, Bruce.
If you know up front that the particle board is coming out, you won't need to be any too careful when you're removing the tack strip and the staples in the pad, as Dan mentioned above.
If you do end up removing the particle board: I just recently helped tear some out, and a combination of moisture and the breakdown of the binders in the particle board had basically glued it to the subfloor! (That was a volunteer community project.)
A personal note: I usually don't weigh in on OT threads, and especially on the N Board (I have a Ferguson TO-20), but this is the first time I've ever had anything semi-meaningful to contribute on a topic, tractor-related or otherwise!