I did this earlier in the week, as my last trip and all of my upcoming are International.

Called the PLT desk. Asked for AAdvantage customer service. The res agent asked if I would tell her what I was calling about, saying, "customer service likes to know before I transfer you over."

Waited a moment. Res agent came back on the line and said that I didn't even need to speak w/ cust. service; I just needed to confirm the number of upgrades I wanted to convert.

I replied, "all the earned ones."

Upgrades were deducted from my account that day. Miles showed up today!