Special Power of Attorney for estate management overseas

Hello,

My father a Philippine citizen and my stepmother American citizen who were married had bought some rural property. That property has been sold by my brothers still residing in the Philippines. My siblings and I reside in the U.S. and are U.S. citzens. I reside in California. My siblings in the U.S. reside in Texas and New Jersey. We don't want to have any claim to our father's estate. Our stepmother passed away this year too, and she didn't want any claims to the property.

My brother is asking us to sign waivers to the heirship and waive our claims to the property. The government had foreclosed on it because they hadn't paid the property taxes. Now they have a new buyer that is willing to pay more than the previous bidders and give my remaining siblings a bit more. We have limited time until the transaction closes so can my siblings in the U.S. give me Special Power of Attorney so that I can have the waivers we were sent ''Declaration of Heirship Extra-Judicial Settlement of State and Waiver of Rights'' signed and notarized at the Philippine consulate? How do they get such a form for this one-time use of authority?

thanks,

--name removed--Koken